Chapter 3. Replacing a drive in a mirrored configuration This chapter describes how to replace a failing hard drive in a mirrored configuration. Mirroring is used to increase the data availability, but you should always have a backup ready just in case something really wrong happens. In a non-mirrored configuration, if a hard drive dies, your only solution is pretty much the backup. In a mirrored configuration, this failure should be transparent to users, and you should be able to replace the disk without loosing any data. Based on your version of AIX, this procedure can be quite simple with AIX Version 4.3.3 and the replacepv command, or more complex with a sequence of commands in earlier versions of AIX. 3.1 Replace a failed physical volume This first section describes how to replace a failing disk in AIX Version 4.3.2 and lower. Assume that we have a system, with one physical volume (hdiskn), which is part of a volume group (asgard_vg) and contains mirrored copies of logical volumes as well as parts of un-mirrored logical volumes. 3.1.1 Step 1 We will remove any copies of logical volumes that reside on the failed physical volume. For example, we have a logical volume called mirrorlv, which had two copies, one on hdiskn and one on hdiskm. Therefore, the new maximum number of logical partition copies is one: