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
Using persistent attributes
You can define volume allocation attributes so they can be reused in subsequent operations. These attributes are called persistent attributes, and they are stored in a set of hidden volume tags. The persist attribute determines whether an attribute persists, and how the current command might use or modify preexisting persisted attributes. You can specify persistence rules in defaults files, in rules, or on the command line. For more information, see the vxassist manual page.
To illustrate how persistent attributes work, we'll use the following vxsf_rules
files. It contains a rule, rule1, which defines the mediatype attribute. This rule also uses the persist attribute to make the mediatype attribute persistent.
# cat /etc/default/vxsf_rules volume rule rule1 { mediatype:ssd persist=extended }
The following command confirms that LUNs ibm_ds8x000_0266 and ibm_ds8x000_0268 are solid-state disk (SSD) devices.
# vxdisk listtag DEVICE NAME VALUE ibm_ds8x000_0266 vxmediatype ssd ibm_ds8x000_0268 vxmediatype ssd
The following command creates a volume, vol1, in the disk group dg3. rule1 is specified on the command line, so those attributes are also applied to vol1.
# vxassist -g dg3 make vol1 100m rule=rule1
The following command shows that the volume vol1 is created off the SSD device ibm_ds8x000_0266 as specified in rule1.
# vxprint -g dg3 TY NAME ASSOC KSTATE LENGTH PLOFFS STATE TUTIL0 PUTIL0 dg dg3 dg3 - - - - - - dm ibm_ds8x000_0266 ibm_ds8x000_0266 - 2027264 - - - - dm ibm_ds8x000_0267 ibm_ds8x000_0267 - 2027264 - - - - dm ibm_ds8x000_0268 ibm_ds8x000_0268 - 2027264 - - - - v vol1 fsgen ENABLED 204800 - ACTIVE - - pl vol1-01 vol1 ENABLED 204800 - ACTIVE - - sd ibm_ds8x000_0266-01 vol1-01 ENABLED 204800 0 - - -
The following command displays the attributes that are defined in rule1.
# vxassist -g dg3 help showattrs rule=rule1 alloc=mediatype:ssd persist=extended
If no persistent attributes are defined, the following command grows vol1 on hard disk drive (HDD) devices. However, at the beginning of this section, mediatype:ssd was defined as a persistent attribute. Therefore, the following command honors this original intent and grows the volume on SSD devices.
# vxassist -g dg3 growby vol1 1g
The following vxprint command confirms that the volume was grown on SSD devices.
# vxprint -g dg3 TY NAME ASSOC KSTATE LENGTH PLOFFS STATE TUTIL0 PUTIL0 dg dg3 dg3 - - - - - - dm ibm_ds8x000_0266 ibm_ds8x000_0266 - 2027264 - - - - dm ibm_ds8x000_0267 ibm_ds8x000_0267 - 2027264 - - - - dm ibm_ds8x000_0268 ibm_ds8x000_0268 - 2027264 - - - - v vol1 fsgen ENABLED 2301952 - ACTIVE - - pl vol1-01 vol1 ENABLED 2301952 - ACTIVE - - sd ibm_ds8x000_0266-01 vol1-01 ENABLED 2027264 0 - - - sd ibm_ds8x000_0268-01 vol1-01 ENABLED 274688 2027264 - - -