VERITAS Volume Manager 4.1 Migration Guide

Converting LVM to VxVM

Converting LVM Volume Groups to VxVM Disk Groups

Chapter 2 7

You can also list the LVM disks with the following VxVM command:

# vxdisk list

2. Analyzing an LVM volume group to see if conversion is possible

After you have selected a volume group for conversion, you need to analyze it to determine if

conversion for VxVM use is possible.

Use the analyze option of vxvmconvert to check for problems that would prevent the

conversion from completing successfully. This option checks for all the conditions listed in

“Volume Group Conversion Limitations” on page 5.

The analysis calculates the space required to add the volume group disks to a VxVM disk

group, and to replace any existing disks and volumes with VxVM volumes, plexes, and

subdisks. If you don't have the required space to convert the disks, the conversion would fail.

Analysis can be run on a live system while users are accessing their data. To analyze LVM

volume groups, choose option 1 of the vxvmconvert utility.

NOTE The analysis option is presented as a separate menu item in vxvmconvert, but

there is an implicit analysis with any conversion. If you simply select the

"Convert LVM Volume Groups to VxVM" menu option, vxvmconvert will go

through analysis on any group you specify. When you are using the convert

option directly, you are given a chance to abort the conversion after analysis,

and before any changes are committed to disk. For more information, see

“Converting LVM Volume Groups to VxVM Disk Groups” on page 5".

The analysis option is useful when you have a large number of groups/disks for

conversion and some amount of planning is needed before the actual

conversion. Installations with many users or critical applications can use the

analyze option on a running system. Then conversion downtime can be better

planned and managed. Smaller conﬁgurations may be better served by using

the convert option directly while in a downtime period.

Sample examples of the analyze option are shown in “Examples” on page 20.

3. Taking actions to make conversion possible if analysis fails

Analysis may fail for any of the reasons listed in the section “Volume Group Conversion

Limitations” on page 5.

Messages from vxvmconvert will explain the type of failure and any actions that can be taken

before retrying the analysis. See “Conversion Error Messages” on page 77 for complete details

of speciﬁc error messages and actions.

4. Backing up your LVM conﬁguration and user data