Changing A Volume's Read-Ahead Cache Settings - HP 2000fc Reference Manual

3. Select the volume to rename.
4. In the Change Volume Name field, type a new name.
The name is case sensitive and can include 20 characters, but not comma, quotation
mark ("), or backslash.
5. Click Change Volume Name.
When processing is complete, the new name is displayed in the Volume Menu panel.

Changing a Volume's Read-Ahead Cache Settings

As an Advanced Manage user, you can optimize a volume for sequential reads or
streaming data by changing its read-ahead cache settings. The read-ahead cache
settings enable you to change the amount of data read in advance after two back-to-
back reads are made. Read ahead is triggered by two back-to-back accesses to
consecutive logical block address (LBA) ranges. Read ahead can be forward (that is,
increasing LBAs) or reverse (that is, decreasing LBAs). Increasing the read-ahead
cache size can greatly improve performance for multiple sequential read streams.
However, increasing read-ahead size will likely decrease random read performance.
The default read-ahead size, which sets one chunk for the first access in a sequential
read and one stripe for all subsequent accesses, works well for most users in most
applications. The controllers treat volumes and mirrored virtual disks (RAID 1)
internally as if they have a stripe size of 64 Kbyte, even though they are not striped.
Caution – Only change the read-ahead cache settings if you fully understand how
the host operating system, application, and adapter move data so that you can adjust
the settings accordingly. Be prepared to monitor system performance using the
virtual disk statistics and adjust read-ahead size until you find the optimal size for
your application.
To change a volume's read-ahead cache settings:
1. Select Manage > Volume Management > Volume Menu > Read Ahead Cache.
For each virtual disk, the virtual disk panel shows a status icon; the name, RAID
level, size, number of disk drives, and number of volumes; and utility status, if any.
2. Select a virtual disk.
The selected virtual disk's volume names, sizes, and read-ahead cache sizes are
displayed, and the amount of free space.
Chapter 3 Managing Storage 89