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Before upgrading the IDEATA drivers on an existing server, do a full backup twice. Verify one of the backups. I’ve seen a few instances where upgrading the drivers could corrupt data already on the drives. While that’s a rare occurrence, taking appropriate precautions will keep you from losing data.

Why are SCSI (or Fiber Channel) drives are preferable to ATA/SATA drives for a server?

- Most ATA (the proper name for “IDE”) interface drives are generally designed for 10 hour per day (typical workstation) usage, SCSI drives are generally designed for 24/7 (server) usage. Servers generally run more than 12 hours per day, most run 24 hours per day.

- SCSI drives (actually SCSI controllers) usually operate in ‘bus master’ (a.k.a. DMA) mode, which improves performance significantly. ATA drives operate in PIO (Programmed I/O) mode unless the controller, drive, and drivers all support DMA/UDMA mode. If you’re using a modern ATA drive with UDMA support in the drive, controller, and driver, then performance should be similar to SCSI. Most inexpensive ISA SCSI controllers and a few PCI SCSI controllers operate in PIO mode, avoid them for servers. Look for ‘bus master’ or DMA in the specifications.

- The maximum sustained throughput of a NetWare server using ATA drives in PIO mode is about 2.5MB/s reading (over 100Mb Ethernet) and 2MB/s writing (1MB/s with mirroring). The same server with (SCSI or ATA) drives using DMA is >8MB/s, more than 3x as fast.

- Mirroring (or duplexing) drives operating in PIO mode slows the throughput even more.

- The above info also applies to Windows and Linux servers, although they are likely to have UDMA drivers available.

- NetWare versions prior to 6.x shipped with IDEATA.HAM and IDEHD.CDM that do not support UDMA, thus unless you’ve upgraded to a newer driver that supports your ATA controller in UDMA mode, any ATA drives will run in PIO mode.

- Therefore, it’s extremely important to make sure you have a supported controller (or that the controller manufacturer provides a driver for your version of NetWare).

- This info generally applies to SATA drives as well as traditional ATA (a.k.a. PATA) drives.

IDE/ATA driver info.

Created from a note posted by Marcel Cox, regarding IDE/ATA support on NetWare 4.x, with modifications by Geoff Strickler.

Novell's IDE support is split into 2 parts:

- the IDE interface driver which is IDEATA.HAM

- the IDE device drivers which are IDEHD.CDM for hard disks and IDECD.CDM for CDROM drives.

Depending on what you want to support, there are certain minimum version requirements on these modules:

A. Supporting disks bigger than 8GB.

To support disks bigger than 8GB, you need IDEHD.CDM 2.0 or newer. The version of IDEATA.HAM does not have any influence on the support disks size. So even if you install the very latest IDEATA.HAM, without an updated IDEHD.CDM, you won't be able to access big disks. OTOH, you should be able to access big disks with an up to date version of IDEHD.CDM, even if you have an old version of IDEATA.HAM

B. UDMA support

To support UDMA, you need IDEATA.HAM 2.0 or later. Note that UDMA drives will also work if you are using old versions of IDEATA.HAM. It's just that NetWare will use PIO mode to access the disk and the access will be very slow. It will however work. A new IDEATA.HAM is not an absolute requirement for UDMA disks. It's just a recommendation for best performance. Of course, the IDE controller must also support UDMA and must be supported by IDEATA.HAM. If a new IDEATA.HAM finds an unknown IDE controller, it will only use the slow PIO mode, even when the controller supports UDMA.

The latest IDE drivers can be found here:

http://developer.novell.com/devres/storage/drivers/index.html - Novell

Note however that these drivers will not work on a NW 4.x server if you didn't install the latest NWPA support files first (disk & LAN driver update from SP8a) or NWPAUP1a

The following web page contains a special edition of the IDEATA.HAM driver for old NetWare versions (3.12, 4.1x, 4.2, 5.0). This version supports >128GB drives, and it supports most UDMA capable controllers, including some SATA controllers. http://www.huweb.hu/maques/nwudma.htm

Additional notes:

1) If you have already partitioned a drive under NetWare with the older IDEHD.CDM, replacing the version will NOT let you extend the size of the partition.

2) If you are doing an original install of 4.11 and the boot drive is going to be a >8G EIDE drive the following approach should work:

Get a copy of IDEHD.CDM v2.00a and copy it to a floppy disk. Start the normal NetWare installation up to the point after the IDE drivers have been detected and loaded. Then use ALT-TAB to switch to the server console and type:

UNLOAD IDEHD

LOAD a:IDEHD

Use ALT-TAB to switch back to the installation program and continue the installation. Once your installation is finished, copy the new IDEHD.CDM to c:\nwserver before rebooting your server. For UDMA support, install NW4SP9 (but not if your server is SBS 4.x).

3) I [Geoff] recommend testing for correct operation after upgrading to a new IDEATA driver. This is best done immediately after installation, before the server is put (back) into production. My HDTEST utility is one excellent way to test for proper operation (and performance).

Note1: UDMA disks will also work without UDMA enabled driver.

Note2: IDEHD.CDM v2.00a is included in included in all NW 4.11 support packs between SP6 and SP9 as well as in the file NWPAUP1A.EXE

Note3: Do not use IDEHD.CDM v3.x for installation. It will not run on an unpatched NW 4.11 server.

General note: Using drivers from

http://developer.novell.com/devres/storage/drivers/index.html#Novell directly is for experts only. If you don't have the correct patches installed, these drivers will not load on NW 4.x. The safer method to get the latest IDE drivers is to install NW4SP9 (note that SBS 4.x may have licensing issues if you apply sp7 or later, sp6a is recommended for SBS 4.x servers). NW4SP8a does not add any direct benefit regarding IDE speed.

If you don't want to reinstall, you might be able to get by using one of the following utilities to expand the existing partition. I haven’t tested this, use at your own risk. As always, if you have important data on the server, backup (twice) and verify before you use any such utility.

ServerMagic (from http://www.powerquest.com) PowerQuest was purchased by Symantec, product may be discontinued.

Storage Manager (from http://www.portlock.com)

RESIZE.EXE (free from http://www.snapback.com as part of their “disaster recovery toolkit”)