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
Controlling raw device access for an existing volume set
To enable or disable raw device node access for an existing volume set, use the following command:
# vxvset [-g diskgroup] [-f] set makedev={on|off} vset
The makedev attribute can be specified to the vxvset set command to create (makedev=on) or remove (makedev=off) the raw device nodes for the component volumes of a volume set. If any of the component volumes are open, the -f (force) option must be specified to set the attribute to off.
Specifying makedev=off removes the existing raw device nodes from the /dev/vx/rdsk/diskgroup directory.
If the makedev attribute is set to off, and you use the mknod command to create the raw device nodes, you cannot read from or write to those nodes unless you set the value of makedev to on.
The syntax for setting the compvol_access attribute on a volume set is:
# vxvset [-g diskgroup] [-f] set \ compvol_access={read-only|read-write} vset
The compvol_access attribute can be specified to the vxvset set command to change the access mode to the component volumes of a volume set. If any of the component volumes are open, the -f (force) option must be specified to set the attribute to read-only.
The following example sets the makedev=on and compvol_access=read-only attributes on a volume set, myvset2, in the disk group, mydg:
# vxvset -g mydg set makedev=on myvset2
The next example sets the compvol_access=read-write attribute on the volume set, myvset2:
# vxvset -g mydg set compvol_access=read-write myvset2
The final example removes raw device node access for the volume set, myvset2:
# vxvset -g mydg set makedev=off myvset2