Adaptec 7800 Family Manager for NetWare 3.1x - Driver Version 1.12
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Driver Name: AIC7870.DSK
Driver Revision: 1.12
Supported Host Adapters: AHA-2940, AHA-2940W, AHA-2944, AHA-2944W,
AHA-2910, AHA-2940Ultra Wide,
AHA-3940, AHA-3940W,
AIC-7870, AIC-7880, AIC-7850
Loading The Driver: "load [path] aic7870 [options]"
Certification Status: Driver has been submitted for Novell Certification.
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This subdirectory contains the driver for Adaptec's AIC-7800 Family of Host
Adapters for NetWare 386 v3.11 and v3.12 SCSI and Advanced SCSI Programming
Interface (ASPI) managers. All of Adaptec's NetWare 386 drivers have full
support for standard SCSI disk drives, "NetWare Ready" drives, and removable
media disk drives (including optical drives).
The driver also contains a built-in ASPI manager. This allows for other
NetWare Loadable Modules (NLMs) to gain access to the host adapter.
Given the flexibility of ASPI, several companies are currently providing
server-based tape backup solutions through ASPI. SBackup is a server based
tape backup solution which is shipped by Novell with NetWare 3.11. SBackup
supports the ASPI interface. There are other ASPI modules already developed
or under development. A programming specification is available from Adaptec
if you are interested in writing your own NetWare 386 ASPI module.
If your file server does a lot of IO operations and you want to try optimizing
its performance, you can adjust the "max_tags=?" and "max_notags"
command line switch. These switches control the maximum number of tagged
and non-tagged commands outstanding at a given device, respectively.
Refer to your disk-drive's documentation to determine if tagged-queuing is
supported, and the maximum number of outstanding commands supported.
Default values are 16 and 2, respectively.
Examples of changing this feature are below:
:load aic7870 max_tags=2 max_nontags=1
:load aic7870 tag_disable=ffff max_nontags=1
The first example is set for tag-queuing drives and the second case is for
non-tag-queuing drives. The max_tags parameter can be set between 1 and 32.
The max_non_tags parameter can be set as 1 or 2. Larger values give
the drives more opportunity for optimization, but take up more memory
in the server.
For several reasons, you may want to use a lower value of max_tags.
For some drives, maximum performance is achieved with
a max_tags less than the maximum supported by the drive.
Also, some drives may not support the driver's maximum count of 32,
or may suffer starvation problems with large counts, leading to
drive deactivation.
The second example turns off tagged-queuing for all devices. This may be
necessary for starvation-prone drives.
Note: To use a read ahead buffer for the CD-ROM, it is necessary to first
lock the CD-ROM. Mounting a volume will typically do this automatically.
Check monitor.nlm for the lock status of the device.
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The following table shows default values for driver command line options.
It was inadvertently left out of the NetWare section of your manual. Please
refer to the following table for the default values.
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OPTION DEFAULT VALUE RANGE
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slot n/a 16-41, 116-141, etc.
verbose n y,n
removable on on,off
fixed_disk on on,off
dev_enable ffh 00-ffh (bitmask)
tag_disable 00h 00-ffh (bitmask)
start_unit* 00h 00-ffh (bitmask)
lun_enable 01h 00-ffh (bitmask)
(default is lun 0 only)
io_combine 32 1-32 (decimal)
max_sectors 256 1-256 (decimal)
max_tags 16 1-32 (decimal)
max_nontags 2 1-2 (decimal)
read_after_write 1 0,1 (1=write and verify,
0=write only)
instr 0 0,1 (1=turn on performance
instrumentation)
Note: Bitmask ranges are 0-ffff for wide products (e.g. 2940W),
with the exception of lun_enable. This mask is used for 8 LUNs,
not targets, and is thus a 8-bit quantity for both narrow and
wide products.
*- The start_unit switch also exists for aspicd.dsk. In this case,
the default is ffffh (all targets). It may need to be turned off
to avoid SCSI bus hangs caused by multiple-LUN CD-ROM's. The start_unit
switch on aic7870.dsk will not filter commands intended for CD-ROM's.
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