AIX Tip of the Week: Configuring LVM Filesystems for Maximimum Disk Availability
Audience: Systems Administrators
Date: March 1999
The following item was found on an internal IBM web site. It describes how to configure RS/6000 disk drives for the maximum AVAILABILITY. You will note that these settings tradeoff I/O performance for availability.
- Use 3 copies.
- Write-verify: YES. Verify each write by performing a follow-up read.
- INTER-policy: MINIMUM. This specifies that only as many physical volumes as there are copies should be used to
- contain the logical volume.
- Scheduling Policy: SEQUENTIAL. This requires the write of each copy to be performed sequentially, increasing the
likeliness that at least one copy completes prior to a system failure. (Comment: this setting limits reads from
only the primary mirror. In contrast, the PARALLEL option allows reads to occur from any mirror copy, which can improve read
- Allocate each logical partition copy on a separate disk: YES. This setting will not allow any two copies of the same
data to reside on the same disk.