VERITAS Volume Manager 3.5 Migration Guide (September 2004)

Chapter 2

Converting LVM to VxVM

Converting LVM Volume Groups to VxVM Disk Groups

Conversion Process Summary

Several steps are used to convert LVM volume groups to VxVM disk groups. Most of these steps can be done

with the vxvmconvert utility. All the steps are not compulsory, and some may have to be followed only if there

are problems during conversion. Some of them (e.g. backing up user data) are left to you to accomplish

through your regular administrative processes.

The steps in the conversion process are:

Step 1. Identifying LVM volume groups for conversion.

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

Step 3. Taking actions to make conversion possible if analysis fails.

Step 4. Backing up your LVM conﬁguration and user data.

Step 5. Planning for new VxVM logical volume names.

Step 6. Stopping application access to volumes in the volume group to be converted.

Step 7. Converting a volume group.

Step 8. Taking actions if conversion fails.

Step 9. Implementing changes for new VxVM logical volume names

Step 10. Restarting applications on the new VxVM volumes.

Step 11. Tailoring your VxVM conﬁguration.

These steps are described in detail in later sections of this chapter. Annotated examples on how to use

vxvmconvert are shown in “Examples” on page 22. For information on restoring back to your original LVM

conﬁguration refer to “Restoring the LVM Volume Group Conﬁguration” on page 19.

Conversion Steps Explained

1. Identifying LVM disks and volume groups for conversion

The obvious ﬁrst step in the conversion process is to identify what you want to convert. The native LVM

administrative utilities like vgdisplay and SAM can help you identify candidate LVM volume groups as well

as the disks that comprise them.

You can also use the vxvmconvert and vxdisk commands to examine groups and their member disks. The

information presented through the vxvmconvert and vxdisk utilities and their interpretation is shown in

“Examples” on page 22.

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 11.