Veritas™ Volume Manager Administrator's Guide
- Understanding Veritas Volume Manager
- VxVM and the operating system
- How VxVM handles storage management
- Volume layouts in VxVM
- Online relayout
- Volume resynchronization
- Dirty region logging
- Volume snapshots
- FastResync
- Provisioning new usable storage
- Administering disks
- Disk devices
- Discovering and configuring newly added disk devices
- Discovering disks and dynamically adding disk arrays
- How to administer the Device Discovery Layer
- Changing the disk-naming scheme
- Adding a disk to VxVM
- Rootability
- Displaying disk information
- Removing disks
- Removing and replacing disks
- Administering Dynamic Multi-Pathing
- How DMP works
- Administering DMP using vxdmpadm
- Gathering and displaying I/O statistics
- Specifying the I/O policy
- Online dynamic reconfiguration
- Reconfiguring a LUN online that is under DMP control
- Creating and administering disk groups
- About disk groups
- Displaying disk group information
- Creating a disk group
- Importing a disk group
- Moving disk groups between systems
- Handling cloned disks with duplicated identifiers
- Handling conflicting configuration copies
- Reorganizing the contents of disk groups
- Destroying a disk group
- Creating and administering subdisks and plexes
- Displaying plex information
- Reattaching plexes
- Creating volumes
- Types of volume layouts
- Creating a volume
- Using vxassist
- Creating a volume on specific disks
- Creating a mirrored volume
- Creating a striped volume
- Creating a volume using vxmake
- Initializing and starting a volume
- Using rules and persistent attributes to make volume allocation more efficient
- Administering volumes
- Displaying volume information
- Monitoring and controlling tasks
- Reclamation of storage on thin reclamation arrays
- Stopping a volume
- Resizing a volume
- Adding a mirror to a volume
- Preparing a volume for DRL and instant snapshots
- Adding traditional DRL logging to a mirrored volume
- Enabling FastResync on a volume
- Performing online relayout
- Adding a RAID-5 log
- Creating and administering volume sets
- Configuring off-host processing
- Administering hot-relocation
- How hot-relocation works
- Moving relocated subdisks
- Administering cluster functionality (CVM)
- Overview of clustering
- Multiple host failover configurations
- CVM initialization and configuration
- Dirty region logging in cluster environments
- Administering VxVM in cluster environments
- Changing the CVM master manually
- Importing disk groups as shared
- Administering sites and remote mirrors
- About sites and remote mirrors
- Fire drill - testing the configuration
- Changing the site name
- Administering the Remote Mirror configuration
- Failure and recovery scenarios
- Performance monitoring and tuning
- Appendix A. Using Veritas Volume Manager commands
- Appendix B. Configuring Veritas Volume Manager
Renaming a disk group
Only one disk group of a given name can exist per system. It is not possible to import or deport a disk group when the target system already has a disk group of the same name. To avoid this problem, VxVM allows you to rename a disk group during import or deport.
To rename a disk group during import, use the following command:
# vxdg [-t] -n newdg import diskgroup
If the -t option is included, the import is temporary and does not persist across reboots. In this case, the stored name of the disk group remains unchanged on its original host, but the disk group is known by the name specified by newdg to the importing host. If the -t option is not used, the name change is permanent.
For example, this command temporarily renames the disk group, mydg, as mytempdg on import:
# vxdg -t -n mytempdg import mydg
To rename a disk group during deport, use the following command:
# vxdg [-h hostname] -n newdg deport diskgroup
When renaming on deport, you can specify the -h hostname option to assign a lock to an alternate host. This ensures that the disk group is automatically imported when the alternate host reboots.
For example, this command renames the disk group, mydg, as myexdg, and deports it to the host, jingo:
# vxdg -h jingo -n myexdg deport mydg
You cannot use this method to rename the active boot disk group because it contains volumes that are in use by mounted file systems (such as /). To rename the boot disk group, boot the system from an LVM root disk instead of from the VxVM root disk. You can then use the above methods to rename the boot disk group.
To temporarily move the boot disk group, bootdg, from one host to another (for repair work on the root volume, for example) and then move it back
- On the original host, identify the disk group ID of the bootdg disk group to be imported with the following command:
# vxdisk -g bootdg -s list dgname: rootdg dgid: 774226267.1025.tweety
In this example, the administrator has chosen to name the boot disk group as rootdg. The ID of this disk group is 774226267.1025.tweety.
This procedure assumes that all the disks in the boot disk group are accessible by both hosts.
- Shut down the original host.
- On the importing host, import and rename the rootdg disk group with this command:
# vxdg -tC -n newdg import diskgroup
The -t option indicates a temporary import name, and the -C option clears import locks. The -n option specifies an alternate name for the rootdg being imported so that it does not conflict with the existing rootdg. diskgroup is the disk group ID of the disk group being imported (for example, 774226267.1025.tweety).
If a reboot or crash occurs at this point, the temporarily imported disk group becomes unimported and requires a reimport.
- After the necessary work has been done on the imported disk group, deport it back to its original host with this command:
# vxdg -h hostname deport diskgroup
Here hostname is the name of the system whose rootdg is being returned (the system name can be confirmed with the command uname -n).
This command removes the imported disk group from the importing host and returns locks to its original host. The original host can then automatically import its boot disk group at the next reboot.
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