Volume group conversion limitations
Some LVM volume configurations cannot be converted to VxVM. The following are some reasons why a conversion might fail:
The volume group has insufficient space for its configuration data. During conversion, the areas of the disks that used to store LVM configuration data are overwritten with VxVM configuration data. If the VxVM configuration data that needs to be written cannot fit into the space occupied by LVM configuration data, the volume group cannot be converted unless additional disks are specified.
A volume group contains a root volume. The
vxvmconvert utility does not currently support conversion to VxVM root volumes. The root disk can be converted to a VxVM volume if it is not an LVM volume.
There is insufficient space on the root disk to save information about each physical disk. For large volume groups (for example, 200GB or more total storage on twenty or more 10GB drives), the required space may be as much as 30MB.
An attempt is made to convert a volume which contains space-optimized snapshots. Such snapshots cannot be converted. Remove the snapshot and restart the conversion. After conversion, use the features available in VxVM to create new snapshots.
Unsupported devices (for example, Linux metadevices or RAM disks) are in use as physical volumes.
To create a VxVM private region, the
vxvmconvert utility can use the LVM2
pvmove utility to move physical extents across a disk. This requires that the
dm_mirror device mapper is loaded into the kernel. If extent movement is required for an LVM volume, you are instructed to use the
vgconvert utility to convert the volume group to an LVM2 volume group.
You can use the analyze option in
vxvmconvert to help you in identifying which volume groups can be converted.
See "Examples of second stage failure analysis" on page 538.