VERITAS Volume Manager 5.0 Migration Guide (September 2006)

25Converting LVM to VxVM
Converting LVM volume groups to VxVM disk groups
Over time, the ultimate goal should be that the underlying VxVM naming is used by all
applications, and that there are no indirect references to those volumes.
6. Stopping application access to volumes in the volume group to
be converted
No applications can be active on the LVM volume group undergoing conversion. Before
attempting to convert any volume group, you must ensure that applications using that
group are down. This involves stopping databases, unmounting file systems, etc.
Note: If you are converting a volume with swap space on it, the conversion requires a
reboot. The swap space cannot be taken out of control of the operating system with a
shutdown to single user mode.
As described in “Conversion and reboot” on page 25,
vxvmconvert tries to unmount
mounted file systems during the conversion. Bear in mind though, that
vxvmconvert
makes no attempt to close down running applications on those file systems, nor does it
attempt to deal with applications (e.g., databases) running on raw LVM volumes.
Note: It is strongly recommended that you do not rely on vxvmconvert's mechanisms for
unmounting file systems. Conversion will be simpler if you close applications, and
unmount file systems before running vxvmconvert.
To unmount a file system, use the following command:
# umount file-system
Conversion and reboot
During conversion, after the analysis phase is complete, the disks to be converted are
deemed to be conversion ready. The
vxvmconvert program asks if you are ready to
commit to the conversion changes. If you choose to complete the conversion, the system
will try to unmount all of the associated mounted file systems, stop and export the volume
group, and then install the VxVM configuration.
If
vxvmconvert is unable to stop and export volume groups or unmount file systems, the
conversion cannot be completed without rebooting the system. You will have the option of
aborting the conversion or completing the conversion by rebooting the system. If you
choose to reboot,
vxvmconvert will trigger the completion of the conversion
automatically, during reboot, when it can be guaranteed that no processes have access to
the volumes that are being converted.
If you choose to abort rather than reboot to complete the conversion,
vxvmconvert will
return to the main menu.