Symbios Logic SDMS NetWare Tuning Guide                Page  1

Custom Tuning Parameters.

Applicable Driver Version Number:  3.05.12

Last update of this document:      07/28/95


Table Of Contents

1.  Introduction...........................................  3
  1.1.  Device Drivers.....................................  3
    1.1.1.  Peripheral Device Dependent Optimizations .....  4
    1.1.2.  Flexibility....................................  4
    1.1.3.  Overall System Tuning..........................  5
  1.2.  ASPI Support.......................................  5
  1.3.  Power Management...................................  5
  1.4.  Device Statistics                                    5
2.  DOS Access Dependencies................................  6
  2.1.  Supported DOS Configurations.......................  6
  2.2.  SDMS 3.XX BIOS.....................................  6
    2.2.1.  DOS Driver Installation........................  6
    2.2.2.  Currently Supported DOS Drivers................  7
      2.2.2.1.  DOSCAM.SYS.................................  7
      2.2.2.2.  MINICAM.SYS................................  7
      2.2.2.3.  CDROM.SYS..................................  7
      2.2.2.4.  MSCDEX.EXE.................................  7
    2.2.3.  DOS Drivers NOT Supported......................  8
      2.2.3.1.  ASPICAM.SYS................................  8
      2.2.3.2.  SCSIDISK.SYS...............................  8
      2.2.3.3.  ASPI8XX.SYS................................  8
      2.2.3.4.  SYMCD.SYS..................................  8
      2.2.3.5.  SYMDISK.SYS................................  8
    2.2.4.  No DOS Drivers.................................  8
  2.3.  SDMS 4.XX BIOS.....................................  8
    2.3.1.  Default Configuration..........................  8
    2.3.2.  NVRAM..........................................  9
    2.3.3.  DOS Drivers....................................  9
  2.4.  No SDMS BIOS ......................................  9
3.  Loading the Symbios Logic SDMS NetWare drivers......... 10
  3.1.  If using NetWare 3.1X.............................. 10
  3.2.  If using NetWare 4.XX.............................. 10
  3.3.  General Information................................ 11
4.  Memory Allocation...................................... 12
5.  Command Line Options Description....................... 13
  5.1.  Summary of Command Line Options.................... 14
  5.2.  Information Options................................ 14
    5.2.1.  Verbose Mode................................... 14
    5.2.2.  Help Mode...................................... 14


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  5.3.  Device Oriented Options............................ 15
    5.3.1.  Tag Command Queuing............................ 15
    5.3.2.  Depth of Queue Tags............................ 15
    5.3.3.  Queue Tag Type................................. 16
    5.3.4.  Base Timeout................................... 16
    5.3.5.  Sorting of Read requests....................... 16
  5.4.  Flexibility Options................................ 17
    5.4.1.  Shared Interrupts.............................. 17
    5.4.2.  Wide SCSI...................................... 17
    5.4.3.  Number of Error Recovery Retries............... 18
    5.4.4.  Logging of SCSI Errors..........................18
    5.4.5.  Maximum Host Adapters.......................... 19
    5.4.6.  Maximum SCSI IDs............................... 19
    5.4.7.  Maximum LUNs................................... 20
    5.4.8.  Exclusion of Devices........................... 20
  5.5.  System Tuning Options.............................. 21
    5.5.1.  Maximum Block Size for Concatenation........... 21
6.  ASPI Support........................................... 22
7.  Device Statistics...................................... 22
8.  Power Management....................................... 23
  8.1.  Installation....................................... 23
  8.2.  Usage.............................................. 23
  8.3.  PMMAKE.NLM......................................... 23
    8.3.1.  Syntax......................................... 23
    8.3.2.  Input File Format.............................. 24
    8.3.3.  Sample Input File.............................. 24
  8.4.  PMSCHED.NLM........................................ 25
    8.4.1.  Syntax......................................... 25
    8.4.2.  Manual Operation............................... 25
    8.4.3.  Scheduled Operation............................ 25
    8.4.4.  Unloading PMSCHED.NLM.......................... 25
9.  Information Pertaining to a Specific Driver............ 26




Symbios Logic SDMS NetWare Tuning Guide                Page  3

1.  Introduction

        The Symbios Logic solution for NetWare 3.12 Operating 
        System environments consists of a device driver 
        SDMSNET3.DSK and optionally NETASPI3.NLM, PMSCHED.NLM 
        and PMMAKE.NLM.

        The Symbios Logic solution for NetWare 4.XX Operating 
        System environments consists of a device driver 
        SDMSNET4.DSK and optionally NETASPI4.NLM, PMSCHED.NLM 
        and PMMAKE.NLM.

        This document will describe the features and functionality 
        of each of the SDMS NetWare modules.  

        Please note, the SDMSNET3.DSK and SDMSNET4.DSK drivers will 
        be referred to as SDMSNETx.DSK, SDMSNETx, the device driver, 
        or simply the driver throughout this document.  
        The NETASPI3.NLM and NETASPI4.NLM drivers will be referred to
        as NETASPIx.NLM, NETASPIx, or the ASPI driver throughout this
        document.

1.1 Device Driver

        The Symbios Logic SDMSNETx.DSK device drivers support SCSI-2
        compliant disk, CD-ROM and removable media devices.
        A number of different command line options are provided with 
        the Symbios Logic SDMS device drivers for NetWare.  These 
        parameters allow users to fine tune their system for high 
        performance and greater flexibility.  Considerations during 
        the design of the drivers included the behavior of the host 
        systems, the peripherals, the different software components 
        co-existing within the system, and the drivers themselves.

        Most system configurations will have certain features that 
        should be addressed by the SDMS drivers to achieve the best
        possible overall performance for the system.  Some examples 
        of the parameters which may be tuned in the driver are listed 
        below, along with the impact the tuning parameter may have on 
        a system given a particular functionality, or lack thereof.  
        In parentheses following the example are the driver options 
        associated with the example.


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    1.1.1.  Peripheral Device Dependent Optimizations:

        Some devices support SCSI tagged queuing very efficiently, 
        e.g. Symbios Logic (formerly NCR/AT&T) disk array subsystems, 
        while others show a significant degradation in performance when 
        a number of queued requests exceeds a certain value. 
        (qtags, qdepth, qtag_type)

Most disk drives have an onboard read cache that is used by the
        drive controller to read ahead data.  The driver may take 
        advantage of this cache by maximizing the cache hits and 
        ensuring a higher data transfer rate.  However, there are 
        devices that do not have an onboard cache, and implementation 
        of the sorting algorithm results in a greater processing 
        overhead with no advantage, and as such an overall performance
        degradation. (sort)

        Devices differ in their response time to requests.  To ensure 
        that the driver can handle devices with various response times,
        an option to tune the timeout value is available.(timeout)

    1.1.2.  Flexibility

        In order to allow flexibility of control of devices on the 
        system, an option is provided to determine which of the devices
        the driver needs to exclude from taking control over.  This 
        allows independent software vendors to provide value added 
        applications to directly control certain devices (e.g. Backup 
        applications) via the ASPI or the CAM interface.  (xcl) 

        Serious SCSI errors are logged to both the console and system
        error log file by default.  If a device is going bad, these 
        errors may provide forewarning to the user so that the device
        may be replaced before complete failure.  The logging of these
        errors may be turned off to either or both of these locations
        if so desired. (Log_ScsiErrors)

        For embedded systems, or other systems with fixed configura-
        tions, if memory is at a premium, a user can limit the amount 
        of dynamically allocated memory by choosing to set maximum 
        limits on the number of host adapters, devices and logical 
        units to support.  The number of allocated buffers for 
        processing IOs will be reduced, and as a result performance 
        may be affected.(max_hbas, max_id, max_lun)



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    1.1.3.  Overall System Tuning

        A driver designed for a networked file server environment 
        also has to optimize the performance in tandem with the other
        components of the system. In order to avoid monopoly on the 
        I/O bus, users can configure the size of the blocks for 
        transfer across the SCSI bus, ensuring that other components 
        get fair access to the I/O bus.  (Max_kb)

  1.2.  ASPI Support
        The Symbios Logic ASPI interface is provided by NETASPIx.NLM 
        and must be loaded in conjunction with the SDMSNETx.DSK 
        device drivers.  NetWare or 3rd party applications may use the
        interface to communicate with any SCSI-2 device attached to a
        Symbios Logic controller, including SCSI-2 tape devices.  

        At this time, no command line options are available to tune 
        NETASPIx.NLM drivers.

  1.3.  Power Management
        Disk devices registered with the NetWare Operating System by
        the SDMSNETx.DSK drivers and which are capable of supporting
        Power Management may be so managed by two NLMs: PMSCHED.NLM 
        and PMMAKE.NLM. PMSCHED.NLM allows manual control of power 
        management to individual devices while PMMAKE can be used to
        create a schedule for power management of devices.

        Command line options for PMMAKE.NLM and PMSCHED.NLM are 
        described in section 8 of this document.
       
        Please note that Power Management of disk devices connected 
        to Symbios Logic 8xx controllers and controlled by 
        SDMSNETx.DSK is NOT supported in the NetWare 4.10 SFT-III
        environment.

  1.4.  Device Statistics
        Device statistics are gathered on all devices registered by 
        the SDMSNETx.DSK with the NetWare Operating System.  These 
        statistics consist of the number of reads and writes which 
        have been performed on a device and the number of times the
        device has been spun up and spun down.  Statistics may be 
        viewed, toggled on/off or reset from the power management 
        utility PMSCHED.NLM.


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2.  DOS Access Dependencies

        The NetWare Operating System sometimes requires accesses to 
        the DOS partition.  This may be to load a file, to down the 
        server, or for some other reason.  The SDMSNETx.DSK NetWare 
        drivers support several SDMS DOS configurations.  
        SDMSNETx.DSK will detect if a 3.XX or 4.XX BIOS is present 
        on the system.  If a 3.XX BIOS is present, the driver will 
        also detect if any Symbios Logic DOS CAM driver is loaded.

        If there are DOS partitions present on any device controlled 
        by a Symbios Logic controller, an SDMS 3.XX or 4.XX BIOS must
        be present for DOS support.  
        The BIOS will either be integrated in the system BIOS or 
        reside on the controller itself.

        Note: An SDMS BIOS is sometimes referred to as a Boot ROM.

  2.1.  Supported DOS Configurations
        The following are supported DOS configurations by the 
        SDMSNETx.DSK NetWare drivers:

        1)  3.XX BIOS, DOSCAM.SYS
        2)  3.XX BIOS, MINICAM.SYS
        3)  3.XX BIOS, DOSCAM.SYS, CDROM.SYS, MSCDEX.EXE
        4)  3.XX BIOS, MINICAM.SYS, CDROM.SYS, MSCDEX.EXE
        5)  3.XX BIOS, No DOS Drivers
        6)  4.XX BIOS, No DOS Drivers, Default Boot Configuration.

  2.2.  SDMS 3.XX BIOS
        If a 3.XX BIOS is present on a system, an optional Symbios 
        Logic CAM driver (DOSCAM.SYS or MINICAM.SYS) may be loaded in 
        CONFIG.SYS.  In addition, optional drivers for CD-ROM support
        may be loaded.  Each DOS driver supported by the 3.XX BIOS is 
        listed below, along with whether each DOS driver is supported 
        in conjunction with the SDMSNETx.DSK NetWare drivers.

    2.2.1.  DOS Driver Installation
        By default, the DOS 3.XX driver installation procedure 
        installs the Symbios Logic MINICAM.SYS driver for DOS 
        support.  MINICAM.SYS does not support wide or synchronous 
        negotiation for any device.  Since the NetWare SDMSNETx.DSK 
        drivers negotiate for the maximum capabilities supported for 
        each device, it is highly recommended that DOSCAM.SYS be 
        loaded for optimal performance of the NetWare server.



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    2.2.2.  Currently Supported DOS Drivers 
        The 3.XX BIOS currently supports both CAM and ASPI drivers.
        The NetWare drivers in a 3.XX BIOS environment only support
        DOS CAM configurations at this time.  The following are a
        list of currently supported DOS drivers in conjunction with
        SDMSNETx.DSK.

        Note: While DOSCAM.SYS and MINICAM.SYS are both supported
              drivers, their use is mutually exclusive.  Only one
              of these drivers may be loaded on a system.

     2.2.2.1.  DOSCAM.SYS
        This driver, coupled with CDROM.SYS and MSCDEX provides the 
        capability for installing the NetWare operating system from 
        CD-ROM.  In addition, this driver provides wide, fast and 
        synchronous SCSI support for disk devices. The NetWare drivers,
        by default, negotiate to the optimal synchronous, fast and/or 
        wide capability of each device.  Thus less overhead is required
        for DOS accesses, and as a result better performance by the 
        system. For optimal performance, it is strongly recommended 
        that the DOSCAM.SYS driver be loaded in CONFIG.SYS.

      2.2.2.2.  MINICAM.SYS
        MINICAM.SYS, coupled with CDROM.SYS and MSCDEX provides the 
        capability for installing the NetWare operating system from 
        CD-ROM.  It does not provide wide, fast or synchronous SCSI 
        support, so it is strongly recommended that this driver NOT 
        be used, or if necessary, used only for installation of the 
        NetWare operating system.
        Warning:  Performance will be impacted on DOS accesses from
        the NetWare operating system.

      2.2.2.3.  CDROM.SYS
        To install the NetWare operating system from CD-ROM, this 
        driver, in conjunction with MSCDEX.EXE, should be loaded with 
        either DOSCAM or MINICAM.  Once the NetWare operating system
        installation is complete, CDROM.SYS does not need to be loaded.
        The SDMSNETx.DSK NetWare drivers have CD-ROM support built in.

      2.2.2.4.  MSCDEX.EXE
        This driver (provided with DOS) should be used in conjunction 
        with CDROM.SYS in order to install NetWare from a CD-ROM.  Due 
        to a bug in MSCDEX.EXE, it is important that the name assigned 
        to the CDROM device NOT be anything which matches the base 
        name of any file to be installed from the CDROM.  A recommended
        name to assign to the CD-ROM device is MSCD001



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    2.2.3.  DOS Drivers NOT Supported

      2.2.3.1.  ASPICAM.SYS
        The ASPICAM.SYS DOS driver is a DOS CAM to ASPI translator.
        This driver is not currently supported in the NetWare
        environment.

      2.2.3.2.  SCSIDISK.SYS
        The SCSIDISK.SYS drivers provide support for more than 2 HBAs
        and Magneto Optical devices in the DOS environment.  The 
        SDMSNETx.DSK drivers provide equivalent support in the NetWare
        environment, and may cause conflict in access of the MO 
        devices.  Loading of SCSIDISK.SYS in conjunction with the 
        SDMSNETx.DSK drivers is not a supported configuration.

      2.2.3.3.  ASPI8XX.SYS
        The DOS ASPI Manager interface, ASPI8XX.SYS DOS driver in
        conjunction with the SDMSNETx.DSK drivers is currently NOT 
        a supported configuration in a NetWare environment.

      2.2.3.4.  SYMCD.SYS
        The SYMCD.SYS driver is a ASPI based CD-ROM driver.  It 
        requires the ASPI8XX.SYS driver be loaded, and is therefore
        not a currently supported driver.

      2.2.3.5.  SYMDISK.SYS
        The SYMDISK.SYS driver provides support for more than 2 HBAs 
        in the DOS environment as well as Magneto Optical support.  It 
        requires the ASPI8XX.SYS driver be loaded, and is therefore not
        a currently supported driver.

    2.2.4.  No DOS Drivers
        The SDMSNETx.DSK NetWare drivers are capable of functioning 
        independently from any DOS drivers, with the exception of 
        installation of NetWare from CD-ROM. Performance will be 
        impacted on DOS accesses from the NetWare operating system,
        but if memory is premium, then this option is available. 

  2.3.  SDMS 4.XX BIOS
        The SDMS 4.XX BIOS supports two different configurations - 
        default Boot configuration and NVRAM configuration.  Of 
        these two configurations, only the default Boot mode is 
        currently supported by the SDMSNETx.DSK drivers.

    2.3.1.  Default Configuration
        In default boot configuration, the 4.XX BIOS supports up to 
        two Symbios Logic 8XX controllers.  Disk devices are supported
        by the BIOS.  Other SCSI devices are not supported without 
        additional DOS drivers.


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    2.3.2.  NVRAM
        If NVRAM is present on a controller with a 4.XX BIOS, the 
        NVRAM settings must be left in its default configuration 
        in order for the NetWare SDMNETx.DSK drivers to function
        properly.

    2.3.3.  DOS Drivers
        Currently NO DOS drivers are supported in a NetWare 
        configuration utilizing a 4.XX BIOS.  As a result, CD-ROM 
        and Magneto Optical devices cannot be supported in the DOS
        environment if the NetWare SDMSNETx.DSK drivers are to be 
        used.  The NetWare drivers will provide this functionality 
        in the NetWare environment.

        Please note, the 4.XX BIOS may NOT be used in NetWare 
        CD-ROM installations.  Either a 3.XX BIOS must be used for
        CD-ROM installation, or the installation must be performed 
        from flex, over the network, etc.

  2.4.  No SDMS BIOS
        If no 3.XX or 4.XX BIOS is present on a system, the NetWare 
        SDMSNETx.DSK drivers will still properly operate on the 
        system.  In such a configuration, DOS must be installed on a 
        device controlled by a controller which is not based on the 
        Symbios Logic 7xx or 8xx families, for example, an IDE drive.

    For more information about the 3.XX and 4.XX BIOS, refer to 
    the Symbios Logic SDMS Hardware Guide.

    For more information about the DOS drivers, please refer to the DOS
    sections of the Symbios Logic SDMS Users Guide.



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3.  Loading the Symbios Logic SDMS NetWare drivers

  3.1.  NetWare 3.1X

        The following files should be copied to the directory in 
        which the server.exe file resides:

           SDMSNET3.DSK - For general support of SCSI disk and CD-ROM 
                          devices attached to Symbios Logic (NCR) based 
                          PCI-SCSI controllers, such as embedded 
                          controllers on the motherboard  utilizing the 
                          53C800 family of integrated circuits. (53C810, 
                          53C815, 53C820, 53C825 chips) and the 53C800 
                          based family of PCI Host Bus Adapters (8100S, 
                          8150S, 8250S, 8251S, 8251D, etc.).

           NETASPI3.NLM - For ASPI programming interface  support, 
                          including tape support.

        At the NetWare 3.1X prompt, type in 
           load SDMSNET3 <options>
           load NETASPI3  (Only necessary if ASPI support is desired)

        Note:  SDMSNET3.DDI has been provided with the drivers only to
               supply information for NetWare 4.XX installations.  
               This file has no purpose in NetWare 3.1x environments.

  3.2.  NetWare 4.XX

        The following files should be copied to the directory in which
        the server.exe file resides:
           SDMSNET4.DSK - For general support of SCSI disk and CD-ROM 
                          devices attached to Symbios Logic (NCR) based 
                          PCI-SCSI controllers, such as embedded 
                          controllers on the motherboard utilizing the 
                          53C800 family of integrated circuits. (53C810, 
                          53C815, 53C820, 53C825 chips), and the 53C800 
                          based family of PCI Host Bus Adapters (8100S, 
                          8150S, 8250S, 8251S, 8251D, etc.).
           SDMSNET4.DDI - For NetWare 4.XX Installation Support.
           NETASPI4.NLM - For ASPI programming interface support, 
                          including tape support.

        At the NetWare 4.XX prompt, type in 
           load SDMSNET4 <options>
           load NETASPI4 (Only necessary if ASPI support is desired)

        If the system is a NetWare 4.XX SFT-III environment, 
        these files should be copied and loaded on each server.



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  3.3.  General Information 

        These drivers may be loaded only once.  If any changes are 
        necessary to the driver options, then the drivers must be 
        unloaded and then reloaded with the appropriate options.  
        If these changes are to be permanent, and the drivers are 
        loaded automatically at server boot time, then these options 
        must also be specified in the startup.ncf or autoexec.ncf file. 

        For more information on installing and using the Symbios Logic 
        SDMS NetWare drivers, please refer to the NetWare section in 
        the SCSI Device Management System Symbios Logic SDMS 3.0 
        User's Guide.


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4.  Memory Allocation

        The driver allocates memory for certain structures based upon 
        the maximum number of SCSI IDs (max_id), LUNs (max_lun) and 
        paths (max_hbas) that may be used in the system.  The amount 
        of memory allocated is based on the following formula: 

        414 bytes of memory are allocated for the structure, so
           Memory allocated = 414 * max_hbas * max_lun * max_id.

        So for default allocations, the amount of memory allocated is:
           Memory allocated = 414 * 8 * 4 * 32 =  423,936 bytes 
                                               =  414 KB

        If, for example, 
           only one host adapter is installed (or using a Symbios Logic 
               based PCI-SCSI embedded controller and no add in HBAs),
           only one LUN per device will be used, and 
           the bus is narrow (e.g. max. 8 SCSI IDs), 
        then by setting the appropriate options, the amount of memory 
        allocated will be:
           Memory allocated = 414 * 1 * 1 * 8 = 3312 bytes,
                                           approximately 3.2 KB




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5.  NetWare Device Driver Command Line Options Description

        The SDMSNETx.DSK drivers have many tuning parameters, as 
        described below

        Following is a list of tuning parameters available, 
        including the default option and a list of valid options.
        Following each parameter is a description of when a 
        parameter should be used and any impact its use/disuse 
        might incur.

        Any time the driver is attempted to be loaded, the driver
        will load, even if invalid command line options are 
        specified.  The single exception is if help is specified, 
        in which case the driver will not load, irregardless of 
        what other command line options are specified.

        If an invalid command line option is specified, the 
        driver will display the invalid option with a ? following.
        Unload the driver and reload with the corrected command line
        option.  

        If a valid command line option is specified but the 
        assignment is not valid, then an error message will be 
        printed by the driver and the default value will be used.
        Unload the driver and reload with the corrected value for 
        the command line option.

        A few command line options will be recognized by the driver, 
        but ignored.  These instances will not display any information 
        to the console.  These options remain in the driver for 
        backward compatibility or to support the command line options 
        added to the driver load line in the startup.ncf by NetWare on 
        NetWare installation.

        The options described below are used by placing the specified 
        characters on the load command line for the SDMSNETx.DSK driver.
        The command line parameter must be separated from the option by
        an equal sign, and can NOT be separated by spaces, e.g.
            load SDMSNET4.DSK qtags=disable 
        is valid, while 
            load SDMSNET4.DSK qtags = disable 
        is not valid. 
        
        Two command line options do not follow this format.  They 
        are the command line options for verbose mode and help, and 
        their format is a -v or -h respectively.  For example, if the
        Verbose Mode command line option is desired in NetWare 3.1X, 
        the load command line should look like:
           load SDMSNET3 -v


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  5.1.  Summary of Command Line Options
         The following command line options are available in the 
         NetWare SDMSNETx.DSK drivers:
           Options          Default    Brief Description
           -------         --------    -----------------
           qtags            enable     Tagged command queuing
           qdepth               10     Tagged queuing queue depth
           qtag_type        simple     Type of qtags to be issued
           wide             enable     Wide SCSI Support
           sort             enable     IO Sorting
           shared_int      disable     Shared Interrupt support
           max_hbas              8     Maximum number of HBAs
           max_id               32     Maximum number of IDs
           max_lun               4     Maximum number of LUNs
           timeout              30     IO timeout period, seconds
           max_retry             5     Maximum number of IO retries
           max_kb            32767     Maximum IO concatenation size(KB)
           Log_ScsiErrors     both     Logging of serious SCSI errors
           xcl               <none>    Devices to be excluded by driver


  5.2.  Information Options

    5.2.1.  Verbose Mode: 

        Command line option:  -v
        Function:  Display the current settings of all driver options.

        This option will indicate the option settings for this load 
        of the driver.

    5.2.2.  Help Mode: 

        Command line option:  -? or -h
        Function:  Display the options available in the driver.
        Possible Impact:  The driver will not load with -? or -h 
                          specified.

        This option may be specified on the command line for a brief 
        description of each of the options available in the driver, 
        as well as valid values for each option.  If the -? or -h 
        option is specified along with other command line options, 
        the help screen will be invoked. All other options will be 
        ignored and the driver will not be loaded.


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  5.3.  Device Oriented Options:

    5.3.1.  Tagged Queuing: 

        Command line option:  qtags=<option>
        Default value:  enable
        Valid options:  enable, disable
        Function:  Enable/disable tagged queuing for the devices 
        Possible Impact:  Tagged queuing may result in improved I/O
                          throughput in devices that support such an
                          option.

        Enabling the option results in the driver issuing tagged I/O
        requests to the devices that support tagged queuing.  Devices
        that do not support tagged queuing are not issued tagged
        requests.  Depending on the drive controller, throughput
        of the device may be increased by the use of queue tags, 
        although an optimal number of queue tags is based on the 
        specific device type.

    5.3.2.  Depth of Queue Tags: 

        Command line option:  qdepth=<option>
        Default value:  10
        Valid options:  0-128
        Function:  Set the depth of the queue for tagged queuing.
                   This value designates the depth of the queue per 
                   LUN (I_T_L nexus), e.g. this value designates the 
                   depth of the queue per device, or per LUN, if a 
                   device has multiple LUNs.
        Possible Impact:  Used to optimize the performance of 
                          tagged command queuing.

        This option is valid only when tagged queuing (qtags)is
        enabled, which it is by default. 0 is equivalent to 
        qtags=disable, and takes precedence over the setting of the 
        qtags option.  While the actual depth of the queue depends on 
        the specific drive controller, for single drives values of 
        about 10-30 are typically most optimal.  A greater number may 
        be optimal for peripherals such as disk arrays.  Users should 
        experiment with various qdepth values to determine the most 
        optimal performance of their particular setup.  The optimal 
        qdepth value is based on different aspects of the system, 
        including but not limited to: the processor, the available 
        memory, the disk drives, and other peripherals.
        Note:  The driver supports a maximum of 128 qtags per 
               controller at any given time.  The driver may allocate 
               fewer qtags per device if this limit is being reached. 



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    5.3.3  Queue Tag Type:

        Command line option:  qtag_type=<option>
        Default value:  simple
        Valid options:  simple, ordered
        Function:  Specify the type of tagged commands the device shall
                   be issued. 
        Possible Impact:  Ordered type may be required for certain 
                          devices in order to avoid IO starvation.

        This option is valid only when tagged queuing (qtags) is 
        enabled, which it is by default.  Simple qtags are typically the 
        preferred tag type.  It may be necessary to use ordered tags 
        on certain devices in order to avoid IO starvation under 
        extremely heavy IO loads, such as a NetWare remirror process.

    5.3.4.  Base Timeout: 

        Command line option:  timeout=<option>
        Default value:  30 
        Valid options:  Any integer value 30 to 999999999 
        Function:  Specify the minimum value (in seconds) for command 
                   timeout.
        Possible Impact:  Insure system integrity when using a slow 
                          device.

        If a device is slow, this value may be increased to insure 
        the device has adequate time to respond to a command issued 
        to it before the command is timed out.

    5.3.5.  Sorting of Read requests: 

        Command line option:  sort=<option>
        Default value:  enable
        Valid options:  enable, disable
        Function:  Enable/disable sorting of read commands to be 
                   issued to devices.
        Possible Impact:  Enabling will normally yield increased 
                          performance based on the target device 
                          controller.

        If the devices connected to the host adapter(s) are of a 
        non-buffered architecture, such as Symbios Logic 6298 disk 
        array, then sorting of reads may result in a performance 
        degradation, since the absence of cache provides no benefit 
        for sorted requests. In this instance the sort option should 
        be disabled.  On most disk drives, an on-board cache allows 
        for reading ahead of data, and by sorting read requests, the 
        probabilities of achieving a cache hit are greatly increased,
        thus increasing the overall performance of the driver.


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  5.4.  Flexibility Options

    5.4.1.  Shared Interrupts: 

        Command line option:  shared_int=<option>
        Default value:  disable
        Valid options:  enable, disable
        Function:  Support shared interrupts.
        Possible Impact:  Enabling may cause a performance degradation.

        The shared interrupt option should be enabled any time a PCI 
        card other than Symbios Logic controller(s) is added to a 
        system which assigns all PCI cards the same interrupt value.  
        The added card must be able to support shared interrupts. The 
        driver automatically handles the case of more than one Symbios 
        Logic host adapter sharing an interrupt.

    5.4.2.  Wide SCSI: 

        Command line option:  wide=<option>
        Default value:  enable
        Valid options:  enable, disable
        Function:  Enable/Disable support of Wide SCSI.
        Possible Impact:  No Wide SCSI Support available.

        This option specifically allows the user to disable support of
        wide SCSI when using  a wide SCSI controller.  This option 
        should be set to "disable" if a wide SCSI device is present on
        the system, but a narrow SCSI cable is connected somewhere on 
        the bus between the wide SCSI host adapter  and the wide 
        device, thus prohibiting the transfer of wide data.  If this 
        option is set to "disable", the wide device may still be used,
        but all data transferred to/from the device will be narrow 
        (8 bit).  The driver will not initiate a wide SCSI transfer 
        request negotiation.



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    5.4.3.  Number of Error Recovery Retries: 

        Command line option:  max_retry=<option>
        Default value:  5
        Valid options:  0-50
        Function:  Set the maximum limit on the number of times to 
                   retry an IO  on a non sequential access device 
                   in the event of some SCSI error condition.
        Possible Impact:  Setting this to 0 will disable the driver 
                          from retrying an IO in the event of an error.  

        If SCSI error conditions occur on a non sequential access 
        device, the driver will retry an IO operation this number of 
        times, before giving up, and returning the IO to the caller 
        with a failed status.  The caller could be NetWare or an 
        application via the CAM interface, including an IO via the
        NETASPIx.NLM.
        If this option is set to 0, then IOs will not be retried in the 
        event of some error condition.  
        Note: Some SCSI error conditions do not warrant a retry, for 
              example, DATA PROTECT or ILLEGAL REQUEST.  Such conditions 
              are reported but not retried, even for positive values of 
              max_retry.  

    5.4.4.  Logging of SCSI Errors: 

        Command line option:  Log_ScsiErrors=<option>
        Default value:  Both
        Valid options:  Off/Console/Syslog/Both
        Function:  Specify where serious SCSI Errors should be
                   logged
        Possible Impact:  Changing this option may result in this
                          information being lost.

        If SCSI error conditions occur, the driver normally attempts to 
        log a SCSI Error Report describing the event to both the console
        and the system error log file SYS:SYSTEM\SYS$LOG.ERR.  This 
        information can be valuable in determining when a device is 
        having problems.  For example this information can indicate if a 
        device is beginning to fail, and provide the NetWare operator
        the opportunity to replace a device before complete failure.
        With this option you can choose to specify where these messages 
        be logged: Console - the server console only; Syslog - the 
        system error log file only; Both - both the server console and 
        the system error log; or Off - Do not log these error messages
        anywhere.
        Note: This option affects the logging of serious SCSI errors 
              only.  Non SCSI errors are logged to both the console and 
              the system error log.  The logging of these errors cannot
              be modified or turned off.


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    The following three options affect the amount of memory used by 
    the driver.  Please see the section above on memory allocation for 
    information on how memory is allocated by the driver, and to get 
    an approximate feel for the amount of memory which may be saved by
    invoking these parameters.

    Please note that if the product of max_hbas * max_id * max_lun is
    small, e.g. is less than 100, system performance may suffer.  These 
    values determine the number of IO buffers allocated by the driver.
    If few buffers are allocated, the possibility that the driver
    will reach a point in which all these buffers are in use may occur.
    Until some of these buffers are freed, no more IOs can be accepted
    by the driver, thus resulting in performance degradation.

    5.4.5.  Maximum Host  Adapters: 

        Command line option:  max_hbas=<option>
        Default value:  8
        Valid options:  1-8
        Function:  Specify the maximum number of Host Bus Adapters to 
                   support.
        Possible Impact:  If number is reduced, may allow for 
                          reduction in memory used by the driver.
                          Reduction may also result in performance 
                          degradation.

        This parameter may be used to optimize the use of dynamically 
        allocated memory by the driver. If less than 8 Symbios Logic 
        based PCI host adapters, including any on board (built in to) 
        the motherboard, are being used, this parameter will allow for 
        a reduction in the total memory being used for the driver.

    5.4.6.  Maximum SCSI IDs: 

        Command line option:  max_id=<option>
        Default value:  32
        Valid options:  8-32
        Function:  Specify the maximum number of SCSI IDs each host 
                   adapter board should support.
        Possible Impact:  If number is reduced, may allow for 
                          reduction in memory used by the driver.
                          Reduction may also result in performance 
                          degradation.

        This parameter may be used to optimize the use of dynamically 
        allocated memory by the driver.  If all the host adapters, 
        including any SCSI controllers on the motherboard are 
        connected to less than 31 devices, a user can reduce the size 
        of the dynamically allocated memory by setting this value to 
        the maximum number of devices on any of the SCSI controllers. 


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    5.4.7.  Maximum LUNs: 

        Command line option:  max_lun=<option>
        Default value:  4
        Valid options:  1-8
        Function:  Specify the maximum number of LUNs each host 
                   adapter board should support per SCSI id.
        Possible Impact:  If number is reduced, may allow for 
                          reduction in memory used by the driver.
                          Reduction may also result in performance 
                          degradation.

        This parameter may be used to optimize the use of dynamically 
        allocated memory by the driver.  If less than 8 LUNs are being
        used per  Symbios Logic based PCI host adapter SCSI id, this 
        parameter will allow for a reduction in the total memory being 
        used for the driver. 

    5.4.8.  Exclusion of Devices: 

        Command line option:  xcl=<device>[:device ...]
        Default value:  All devices recognized by the driver, i.e. 
                        no devices are excluded.
        Valid options:  p,i,l  
                       (Multiple devices may be specified with a colon
                       separator) where p is the Path designator, and 
                       is in the range 0-7, i is the SCSI ID 
                       designator, and is in the range 0-31, and l 
                       is the LUN designator, and in the range 0-7.  
                       The LUN parameter is optional.
                       Multiple devices may be excluded so long as the
                       string does not exceed 35 characters in length 
                       and devices are separated by colons.  
        Examples:  xcl=1,2,3 to exclude LUN 3 of the device at SCSI 
                                ID 2 on Path 1.
                   xcl=1,2,3:2,5 to exclude LUN 3 of the device at 
                                 SCSI ID 2 on Path 1, and all LUNs on 
                                 the device at SCSI ID 5 on Path 2 
        Function:  Allows for specifying certain devices not be 
                   recognized by the driver.
        Possible Impact:  Device(s) may not be directly accessed via 
                          SDMSNETx.DSK driver.

        This option is available so that specific devices may be 
        excluded from being recognized and directly accessed by the 
        SDMSNETx.DSK drivers.  These devices are not registered with 
        the operating system for use by the driver. Other 
        applications/drivers can then take over the control of such 
        devices. This option is available for support of third party 
        vendors who write their own SCSI control applications.
        A maximum of 5 devices may be excluded.


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  5.5.  System Tuning Options

    5.5.1.  Maximum Block Size for Concatenation: 
        Command line option:  max_kb=<option>
        Default value:  32767
        Valid options:  0-32767
        Function:  Set the maximum number of KB that may be written 
                   to disk at one time.
        Possible Impact:  A high number may result in more data being 
                          transferred in a single data phase.

        Specify the maximum size block in Kilobytes which may be 
        written to disk in one data transfer phase. This ensures 
        that when requests are being concatenated, the maximum size 
        of the concatenated request would not exceed the specified 
        value. If individual requests themselves are greater than this
        specified value, no action would be taken.



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6.  ASPI Support

        The NETASPIx.NLM drivers provide an ASPI interface to the 
        SDMSNETx.DSK drivers.  The ASPI interface is a standard
        interface which is used by many applications, including 
        NetWare SBACKUP and Cheyanne ArcServe tape backup products.

        Please note, only one ASPI interface may be loaded on a 
        single server, therefore if another driver supporting ASPI 
        is loaded, the NETASPIx.NLM driver cannot be loaded, and any
        application utilizing the ASPI interface may not access any 
        device controlled by a Symbios Logic 8xx controller.  The 
        NetWare Operating System will still be able to access any
        device registered by the SDMSNETx.DSK driver.

7.  Device Statistics
        Device Statistics are comprised of the number of reads from 
        and writes to a device as well as the number of times the 
        device has been spun up and spun down.  This information is
        accumulated beginning at the time the device is registered  
        the NetWare Operating System by SDMSNETx.DSK and is 
        continuously accumulated until these statistics are either 
        turned off or reset.  These statistics are available for disk
        devices, CD-ROMs and removable media devices.

        The module PMSCHED.NLM allows viewing of these statistics.
        It also provides a means for resetting or turning off/on 
        these statistics on a per device basis.  A device does not 
        need to be power management capable in order for these
        statistics to be accumulated.

        To reset or turn device statistics on or off on a device, 
        highlight the device under PMSCHED.NLM and press <F3>.  A 
        menu with the selections :
               1) Toggle Power Management
               2) Toggle Statistics
               3) Reset Statistics
        will appear.  Highlight the appropriate option and press 
        return.

        At this time, there is no capability to turn statistics 
        on/off or reset statistics from the scheduler.

        For more information on PMSCHED.NLM, please see section 8.4.


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8.  Power Management
        Power Management support for NetWare is composed of two NLMs,
        PMSCHED.NLM and PMMAKE.NLM.  One or both these NLMs must be 
        used in conjunction with the SDMSNETx.DSK drivers to activate
        power management on disk devices registered by SDMSNETx.DSK with
        the NetWare Operating System.

        SDMS Power Management is supported only on disk devices.
        Some disk devices do not support power management.  If such 
        a device is detected, PMSCHED will indicate the device is 
        not power manageable..

  8.1.  Installation
        1)  Copy PMSCHED.NLM and PMMAKE.NLM to the SYS:\SYSTEM 
            directory of the NetWare server.
        2)  Create a subdirectory SYS:\PM.  This is the directory
            the schedule text and configuration files are expected 
            to reside in.

  8.2.  Usage
        PMMAKE.NLM is used to compile a schedule for power 
        management of devices.  PMSCHED.NLM is used for activation
        of power management and viewing, resetting and turning of 
        statistics off/on.  These two modules should not be loaded 
        at the same time.  If power management is to be used on a 
        regular basis, PMSCHED.NLM may be loaded from the 
        autoexec.ncf file.
        
  8.3.  PMMAKE.NLM
        PMMAKE.NLM utility should be used to compile a power 
        management schedule file from a standard text file, which may
        be created using the NetWare EDIT utility or any editor of
        choice.  The text file should be located in the 
        SYS:\PM directory on the server.  The format for the 
        text file is given below.  

    8.3.1.  Syntax
        The syntax for the PMMAKE.NLM utility is:
            load PMMAKE <input filename> [<output filename>]
        where 
            <input filename> is the full path name of the text file
                             containing the power management 
                             scheduling directives.  If the path is
                             not specified, the NetWare search path 
                             will be used.
            <output filename> is the full path name of the output 
                             configuration (CFG) file to be produced.
                             If the output file name is not specified,
                             the output file produced will be PM.CFG, 
                             located in the SYS:\PM directory.


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    8.3.2. PMMAKE Input File Format
        The format for the PMMAKE input (text) file is

        !<DAY INDICATOR>
        BEGIN, <START TIME>, <DELAY TIME>, <DEVICE LIST>
        END, <STOP TIME>, <DELAY TIME>, <DEVICE LIST>

        DAY INDICATOR = SUN, MON, TUE, WED, THR, FRI, SAT
        START TIME    = 24 Hour time format: 00:00 (Midnight) - 23:59
        STOP TIME     = 24 Hour time format 00:00 (Midnight) - 23:59
        DELAY TIME    = Seconds 1 - 3600
        DEVICE LIST   = ALL | <DEVICE ID>[, <DEVICE ID> ...]
        DEVICE ID     = BxxIxxLxx  
                        where Bxx identifies the bus,
                              Ixx the SCSI ID, and
                              Lxx the LUN
                             (The LUN may be omitted if it is zero.)

        Bus identifiers may be omitted after the first bus identifier.
        Future devices are assumed to be on the same bus until a new 
        bus id is specified,
        E.g. B00I01L01, I02, I03, I04, B01I00, I01, I02 specifies:
             Devices ID 01 LUN 01, ID 2, ID 3, ID 4 on Bus 0
             Devices ID 0, ID 1, ID 2 on Bus 1

    8.2.3. PMMAKE Sample Input File:
        !SUN
        BEGIN, 00:00, 10, ALL
        END,   23:59, 10, ALL

        !MON
        BEGIN, 00:00, 10, ALL 
        END, 06:00, 10, B00I00
        END, 06:30, 10, B00I01  

        BEGIN, 18:00, 10, ALL
        END,   23:59, 10, ALL

        !FRI
        BEGIN, 00:00, 10, ALL
        END, 06:00, 10, B00I00
        END, 06:30, 10, B00I01

        BEGIN, 17:30, 10, B00I01
        BEGIN, 18:00, 10, B00I00
        END,   23:59, 10, ALL

        !SAT
        BEGIN, 00:00, 10, ALL 
        END,   23:59, 10, ALL


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  8.4.  PMSCHED.NLM
        The PMSCHED utility must be loaded for power management to 
        be activated for SDMSNETx.DSK controlled devices.

    8.4.1  Syntax.
        The syntax to load PMSCHED is:
            load PMSCHED [<schedule file>]
        where
            <schedule file> is the name of the power management 
                            configuration file to be used.  If no 
                            file is specified, then PMSCHED looks for
                            SYS:\PM\PM.CFG.  If PM.CFG is not
                            found PMSCHED will load for manual 
                            operation of Power Management

    8.4.2  Manual Operation
.       In this configuration, Power Management will initially be off 
        on all devices, and gathering/displaying of device statistics 
        will be on.
        PMSCHED.NLM allows manual enabling and disabling to power 
        management on a individual drive basis; statistics gathering 
        can be enabled and disabled, and statistics can be cleared.
        (For more information on statistics, please see section 8.)

        To toggle Power Management off and on for a device, highlight
        the device under PMSCHED.NLM and press <F3>.  A menu with 
        the selections:
               1) Toggle Power Management
               2) Toggle Statistics
               3) Reset Statistics
        will appear.  Highlight 'Toggle Power Management' and press 
        return.  Toggling of power management for a device will have
        no effect on the device statistics.

    8.4.3.  Scheduled Operation
        To enable automatic scheduling of power management cycles, 
        PMSCHED must be loaded and remain loaded.  For scheduled 
        operation, PMSCHED.NLM requires either the file 
        SYS:\PM\PM.CFG, created by PMMAKE.NLM, or alternatively 
        PMSCHED be loaded with the name of the schedule file (created
        by PMMAKE.NLM) as a command line parameter.

    8.4.4.  Unloading PMSCHED.NLM
        Unloading of PMSCHED.NLM does not turn Power Management off.
        Instead, the state of power management on each device will 
        be maintained until the server is downed or PMSCHED is 
        reloaded.  


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9.  Information Pertaining to a Specific SDMSNETx.DSK Device Driver

    This document addresses options available on the Symbios Logic 
    SDMS NetWare drivers, version 3.05.12.  For information pertaining 
    to a specific driver, please do one of the following:

        For NetWare version 4.XX, consult the SDMSNET4.DDI file for 
        options available for SDMSNET4.DSK.  This may be accessed via 
        the NetWare install utility.

        For versions of the driver 3.05.00 and later, use the -? 
        option on the command line of the SDMSNETx.DSK driver

