Veritas Storage Foundation 5.1 SP1 Advanced Features Administrator"s Guide (5900-1503, April 2011)

undergoing conversion. Access to the LVM configuration itself (the metadata of
LVM) must also be limited to the conversion process.
Volume group conversion limitations
There are certain LVM volume configurations that cannot be converted to VxVM.
Some of the reasons a conversion could fail are:
A volume group with insufficient space for metadata.
In the conversion of LVM to VxVM, the areas of the disks used to store LVM
metadata are overwritten with VxVM metadata. If the VxVM metadata that
needs to be written will not fit the space occupied by the LVM metadata, the
group containing the disk cannot be converted. If you have just enough space
for the conversion, you probably would want to have more space for future
configuration changes.
Note: The most likely scenario in which a Volume Group cannot be converted,
because of insufficient private space, is when a large HP-UX system using
Extent based Striping is being used
A volume group containing the root volume.
The vxvmconvert command does not convert any volume group that contains
a rootable volume, identified by the presence of the LIF area as created by
mkboot(1M). Not only is the current root volume off limits, but any volume
that might be used as an alternate root volume is rejected as well.
Note: You can use the vxcp_lvmroot(1M) command to create a VxVM root disk
on a spare physical disk from the contents of the existing LVM root disk.
Similarly, you can use the vxres_lvmroot(1M) command to recreate an LVM
root disk on a spare disk from the contents of the VxVM root disk. Additional
information is available on the VxVM root disk.
See the Veritas Volume Manager Administrators Guide.
A volume group containing mirrors using the Mirror Write Cache feature for
volume consistency recovery.
Users should be aware that when converting mirrored LVM volumes to VxVM,
some of these volumes will likely have the Mirror Write Cache consistency
recovery method in force on the volume. The vxvmconvert utility can convert
these volumes, but must use the Dirty Region Logging (DRL) feature to obtain
the same level of functionality. However, since Dirty Region Logging requires
some user space to be available for the log, a conversion could fail due to an
403Offline data migration
Converting LVM to VxVM