Can someone clear this up for me?
Does this article apply to only the physical drive and not the logical
The default on most RAID drive are "Write Through"
So my main question is....

Can I enable "Write Back" on the logical drive setup on NSS for NetWare
6.5 or Linux OES? {Yes I do have a UPS and Battery Backup Cache controller.}

Slow Performance on SCSI Devices and RAID Controllers (Linux)

If you plan to use space from SCSI devices---local or in a RAID
controller---for your NSS pools and volumes on Linux, make sure the
devices and controller use Write-Through cache management, not
Write-Back. Using Write-Back cache management on SCSI drives with a
journaled file system such as NSS can actually degrade file system
performance instead of improving it.

Write-Through and Write-Back (also known as Write-Behind) are cache
management schemes that can affect the manner in which data is written
to the hard drives. Although Write-Back can sometimes improve
performance, it does so by allowing data to be held in cache rather than
being written to disk. Data loss can occur if the server fails before
the cached data is written to disk, such as with a power failure.

To minimize the potential for data loss when Write-Back is being used, a
journaled file system might alter its manner of committing writes to
disk. Instead of improving performance, Write-Back cache management
actually creates work for the journaled file system, and the additional
workload can degrade file system performance. It seems
counter-intuitive, but this additional effort is necessary to help
ensure data integrity. Write-Through cache management assures the file
system that writes are being committed to disk as intended. The
additional effort to protect against potential data loss associated with
Write-Back is no longer required, and the file system performance is not

If the server uses a RAID controller, when configuring the RAID device,
enable Write-Through (disable Write-Back) cache management, using the
controller's BIOS setup routine or configuration utility.

To enable Write-Through cache management for local devices:


Log in to the server as root.

In YaST, open the Various Linux Tools section.

Install the xscsi RPM package, then close YaST.

The xscsi package installs the scsi-config utility in

In a terminal console, enter


Enable Write-Through (disable Write-Back) cache management for
each SCSI device.