AMCC 720-0138-00 manual Name of the unit optional, Stripe size, if appropriate for the RAID level

Chapter 5. Configuring Units

Name of the unit (optional)

Units can be given names. These names will be visible in 3DM.

Stripe size, if appropriate for the RAID level

In general, smaller stripe sizes are better for sequential I/O, such as video, and larger stripe sizes are better for random I/O (such as databases).

Striping size is not applicable for RAID 1, because it is a mirrored array without striping.

Using the default stripe size of 64KB usually gives you the best performance for mixed I/Os. If your application has some specific I/O pattern (purely sequential or purely random), you might want to experiment with a smaller or larger stripe size.

Unit policies

Several unit policies are set when you create a new unit:

•Write Cache (enabled, by default)

•Drive Queuing (disabled, by default).

•Auto Verify (disabled, by default)

•Continue on Source Error During Rebuild (disabled, by default).

•StorSave Profile (Protection, by default)

You can change all of these policies after the unit has been created.

For a summary of what these policies do, see the discussion under “Setting Unit Policies” on page 44. For how to adjust each one, see the procedures later in this chapter.

36 3ware Serial ATA RAID Controller User Guide for the Power Mac G5