AIX LVM: Mechanics of migratepv (III)
The AIX LVM command migratepv can be used to exchange physical volumes in mirror copies of logical volumes. The third part is about the correction of “wrong” mirroring. The possibilities that arise are discussed. The possibilities shown are demonstrated using a larger example from practice.
In practice it occasionally happens that mirrored logical volumes are “incorrectly” mirrored. In the following, “wrong” mirroring is understood to mean that a mirror copy that should only contain physical volumes from one data center also contains physical volumes from another data center. This can happen relatively quickly if no mirror pools are used and logical volumes are extended frequently.
In this article we only consider the case of mirrored logical volumes with 2 mirror copies. In all cases considered, each logical partition has copies in both data centers. In particular, this means that if a data center fails, a valid copy is still available for each logical partition. The aim is to correct this in all of the following examples so that in the end each mirror copy only contains physical volumes of one data center. When correcting the mirroring, it is ensured that copies are always available in both data centers and thus redundancy is provided in the event of failure of one of the two data centers.
For the details see: