HP StorageWorks 2000 Modular Smart Array Reference Guide (481599-003, August 2008)

190 HP StorageWorks 2000 Family Modular Smart Array reference guide • August 2008
Controlling Host Access to the System’s Write-Back
Cache Setting
You can prevent hosts from using SCSI MODE SELECT commands to change the
system’s write-back cache setting. Some operating systems disable write cache. If
host control of write-back cache is disabled, the host cannot modify the cache
setting. The default is Disabled.
This option is useful in some environments where the host disables the system’s
write-back cache, resulting in degraded performance.
To enable or disable host control of write-back cache:
1. Select Manage > General Config > System Configuration.
2. Click Advanced Options.
3. In the SCSI Configuration Options panel, set Host Control Of Write-Back Cache to
Enabled or Disabled.
4. Click Change SCSI Configuration Options.
Changing the Sync Cache Mode Option
Sync Cache Mode controls how the SCSI SYNCHRONIZE CACHE command is
handled. Typically, you do no need to change this option. However, if the system
has performance problems or problems writing to databases or other applications,
contact technical support to determine if you should change this option.
To change the cache synchronization mode:
1. Select Manage > General Config > System Configuration.
2. Click Advanced Options.
3. In the SCSI Configuration Options panel, set Sync Cache Mode to one of the
following options:
■ Immediate – Good status is returned immediately and cache content is
unchanged. This option is the default.
■ Flush To Disk – Good status is returned only after all write-back data for the
specified volume is flushed to disk.
4. Click Change SCSI Configuration Options