LVM – Known Issues / Restrictions

Important reminder about DataKeeper for Linux asynchronous mode in an LVM over DataKeepr configuration

Kernel panics may occur in configurations were LVM resources sit above multiple asynchronous mirrors. In these configurations data consistency may be an issue if a panic occurs. Therefore the required configurations are a single DataKeeper mirror or multiple synchronous DataKeeper mirrors.

Use of lkID incompatible with LVM overwritten on entire disk

When lkID is used to generate unique disk IDs on disks that are configured as LVM physical volumes, there is a conflict in the locations in which the lkID and LVM information is stored on the disk. This causes either the lkID or LVM information to be overwritten depending on the order in which lkID and pvcreate are used.

Workaround: When it is necessary to use lkID in conjunction with LVM, partition the disk and use the disk partition(s) as the LVM physical volume(s) rather than the entire disk.

LVM actions slow on RHEL 6

When running certain LVM commands on RHEL 6, performance is sometimes slower than in previous releases. This can be seen in slightly longer restore and remove times for hierarchies with LVM resources.

The configuration of Raw and LVM Recovery Kits together is not supported in RHEL 6 environment

When creating a Raw resource, the Raw Recovery Kit is looking for a device file based on major # and minor # of Raw device. As the result, /dev/dm-* will be the device; however, this type of /dev/dm-* cannot be handled by the LVM Recovery Kit and a “raw device not found“ error will occur in the GUI.