This document gives some recommendations on improving reliability and performance of NetWare servers using Adaptec AIC78xx based SCSI controllers. This includes most Adaptec AHA29xx and AHA39xx adapters with the exception of the AHA2920A. This information has been gathered from a variety of sources and has not been officially verified by Adaptec or Novell.
There are 2 different families of AIC78xx based controllers, using different drivers:
1/ All Adaptec Ultra2 controllers. For these controllers, the only available driver is AIC78U2.HAM. See the readme file in 7800NW.EXE for a complete list.
2/ All the other AIC78xx based controllers. For these controllers you can choose between the AIC7870.DSK driver or the AHA2940.HAM driver. At the time of writing the latest drivers were:
On Adaptec's web site ( http://www.adaptec.com ), in the file 7800NW.EXE:
AIC78U2.HAM Version: 6.10 (980911) and AIC7870.DSK Version: 4.20 (980902)
On http://support.novell.com/, Minimum Patch List, locate the file IWSP6a.EXE. This file contains:
AIC78U2.HAM Version: 6.00 (980622) and AHA2940.HAM Version: 7.00 (980720)
For those who do not wish to apply the whole Support Pack they are also in nwpaup1a.exe; use the File Finder on the above website to search for it by name.
1) Always use the most current drivers, i.e., AIC7870 (1998) or the .HAM drivers.
2) Some computer manufacturers that integrate Adaptec SCSI controllers on their motherboards have customized their SCSI BIOS to the extent that the controller no longer works with Adaptec drivers. In this case, a customized disk driver has to be used. These customized disk drivers are recognized by an "S" in their version number (eg: AIC7870.DSK v2.13S9). In this case you have to refer to the computer manufacturer for updated drivers.
HAM or DSK drivers ?
For Adaptec Ultra2 SCSI controllers, HAM drivers are the only choice. For the other controllers you have the choice between the AIC7870.DSK driver and the AHA2940.HAM driver (note that with NetWare 5 only HAM drivers are supported). There is no general recommendation on which one is better, but here are some ideas:
- If you decide to use HAM drivers, you should install nwpaup1a.exe or IWSP6a.EXE, with the disk and lan driver update option checked
- In some cases HAM drivers may be faster
- Some third party backup software does not officially support HAM drivers for Adaptec controllers. Some people have reported that these programs work correctly with the nwpaup1a.exe/IWSP6a update. Without the updates these programs may not work reliably.
- HAM drivers are IRQ 15 safe.
SCSI CDROM support
When using HAM drivers, SCSI CDROM support is automatic through the SCSICD.CDM driver provided by Novell. If you are using the AIC7870.DSK driver, however, you may have to enable CDROM support yourself. With older versions of AIC7870.DSK, this was done by loading the ASPICD.DSK driver. Since version 4.0 of AIC7870.DSK, CDROM support is built into the AIC7870.DSK driver. You can enable it by adding the option "cdrom=on" to the line loading the AIC7870.DSK driver (DEFAULT SETTING IS CDROM=ON).
Other important command line options
This option is mandatory for the HAM drivers. In addition, you have to load the HAM driver once for each SCSI controller present in your server, each time with a different SLOT= parameter. For the AIC7870.DSK driver v4.10 or later, the SLOT= parameter is optional. If you specify the SLOT= parameter, you have to load the driver once for each controller in your system. If you omit the SLOT= parameter, loading the driver a single time will handle all controllers supported by this driver.
By using this option, you disable tagged command queuing, an optimization technique which is supposed to improve performance. See TIDs 500362 and 2925042 for more information on issues related to this parameter.
This option is for .DSK drivers only, it will cause the .ham drivers to fail to load if used.
Use this option if you have a device that needs LUN addressing, such as SCSI CDROM changers and external RAID controllers.
CDROM=ON (AIC7870.DSK only)
Use this option to enable support for SCSI CDROM drives. In this case do not load ASPICD.DSK
READ_AFTER_WRITE=0 (AIC7870.DSK only)
Using this option will disable read after write verification at the controller level. All modern SCSI drives do read after write verification at the drive level, and doing it twice results in reduced performance with no gain in data reliability. This performance difference is especially noticeable in mirroring or duplexing configurations; in that situation this option is a must.
If either the controller or the drive are performing Read After Write Verification then the NetWare Set parameter that implements RAWV functionality in the OS should also be disabled; use Servman (NW4.10) or Monitor (NW4.11 or NW5 only) to do this.
For a complete list of command line options, check the file README.TXT included in 7800NW.EXE
HP NetServer 166 LS Page Faults with AIC7870 - TID2919876
HP Server Hang During Remirror - TID2934806
AIC7870 volume disappearing/dismounting - TID2935457
Latest Adaptec 7700&7800 Scsi drivers(8/97) - TID2924897
Servers Hang After IWSP4a Upgrade - TID2936714
LOADER Abends With Support Pack 4 - TID2935517
AUTOEXEC.NCF Not Executing from SYS:SYSTEM - TID2935907
Slow Core Dumps on HP LX Server - TID2935460
Loader cannot find public symbol ASPI_Entry - TID2934553
NetWare Support Pack v6.0 - TID2944744
NWPA.NLM and CDROM.NLM updates - TID2942518
Support Tips For Adaptec EISA, VL, PCI HBAs - TID500362
Adaptec 2940 / Quantum Drives - TID2927805
HP Netserver LH and AIC7870.DSK - scsi errors - TID2925018
EMC Disk Farm parameters - TID2930913
AHA-2940 Hardware Setup Tips - TID1001599
Adaptec 1540 hangs server - TID2928579
ADAPTEC 2940 - TID2919935
ADAPTEC 7870 - TID2926455
Mirroring and Performance - TID2924724
No CDROM Devices Registered With NetWare - TID2921568
HP Netserver Unable to load AIC7870 and HPDA4 - TID2923850
ADAPTEC 2940W redirected blocks - TID2913106
Adaptec and NetWare v3.11 Installation Issues - TID2925042
What is Device Deactivation - TID500051