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
Creating a volume with dirty region logging enabled
Dirty region logging (DRL), if enabled, speeds recovery of mirrored volumes after a system crash. To enable DRL on a volume that is created within a disk group with a version number between 20 and 100, specify the logtype=drl attribute to the vxassist make command as shown in this example usage:
# vxassist [-g diskgroup] make volume length layout=layout \ logtype=drl [nlog=n] [loglen=size] [other attributes]
The nlog attribute can be used to specify 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, the size of the log would need to be 20K for a 10GB volume with a region size of 64 kilobytes.
For example, to create a mirrored 10GB volume, vol02, with two log plexes in the disk group, mydg, use the following command:
# vxassist -g mydg make vol02 10g layout=mirror logtype=drl \ nlog=2 nmirror=2
Sequential DRL limits the number of dirty regions for volumes that are written to sequentially, such as database replay logs. To enable sequential DRL on a volume that is created within a disk group with a version number between 70 and 100, specify the logtype=drlseq attribute to the vxassist make command.
# vxassist [-g diskgroup] make volume length layout=layout \ logtype=drlseq [nlog=n] [other attributes]
It is also possible to enable the use of Persistent FastResync with this volume.
Note:
Operations on traditional DRL log plexes are usually applicable to volumes that are created in disk groups with a version number of less than 110. If you enable DRL or sequential DRL on a volume that is created within a disk group with a version number of 110 or greater, the DRL logs are usually created within the plexes of a version 20 DCO volume.