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
Adding traditional DRL logging to a mirrored volume
A traditional DRL log is configured within a DRL plex. A version 20 DCO volume cannot be used in conjunction with a DRL plex. The version 20 DCO volume layout includes space for a DRL log.
To put dirty region logging (DRL) into effect for a mirrored volume, you must add a log subdisk to that volume. Only one log subdisk can exist per plex.
To add DRL logs to an existing volume, use the following command:
# vxassist [-b] [-g diskgroup] addlog volume logtype=drl \ [nlog=n] [loglen=size]
If specified, the -b option makes adding the new logs a background task.
The nlog attribute specifies the number of log plexes to add. By default, one log plex is added. The loglen attribute specifies the size of the log, where each bit represents one region in the volume. For example, a 10 GB volume with a 64 KB region size needs a 20K log.
For example, to add a single log plex for the volume vol03 in the disk group mydg, use the following command:
# vxassist -g mydg addlog vol03 logtype=drl
When you use the vxassist command to add a log subdisk to a volume, a log plex is created by default to contain the log subdisk. If you do not want a log plex, include the keyword nolog in the layout specification.
For a volume that will be written to sequentially, such as a database log volume, use the following logtype=drlseq attribute to specify that sequential DRL will be used:
# vxassist -g mydg addlog volume logtype=drlseq [nlog=n]
After you create the plex containing a log subdisk, you can treat it as a regular plex. You can add subdisks to the log plex. If you need to, you can remove the log plex and log subdisk.