Storage Foundation 7.4.1 Administrator's Guide - Linux
- Section I. Introducing Storage Foundation
- Overview of Storage Foundation
- How Dynamic Multi-Pathing works
- How Veritas Volume Manager works
- How Veritas Volume Manager works with the operating system
- How Veritas Volume Manager handles storage management
- Volume layouts in Veritas Volume Manager
- Online relayout
- Volume resynchronization
- Dirty region logging
- Volume snapshots
- FastResync
- How VxVM handles hardware clones or snapshots
- Volume encryption
- How Veritas File System works
- Section II. Provisioning storage
- Provisioning new storage
- Advanced allocation methods for configuring storage
- Customizing allocation behavior
- Using rules to make volume allocation more efficient
- Understanding persistent attributes
- Customizing disk classes for allocation
- Specifying allocation constraints for vxassist operations with the use clause and the require clause
- Creating volumes of a specific layout
- Customizing allocation behavior
- Creating and mounting VxFS file systems
- Creating a VxFS file system
- Mounting a VxFS file system
- tmplog mount option
- ioerror mount option
- largefiles and nolargefiles mount options
- Resizing a file system
- Monitoring free space
- Extent attributes
- Section III. Administering multi-pathing with DMP
- Administering Dynamic Multi-Pathing
- Discovering and configuring newly added disk devices
- About discovering disks and dynamically adding disk arrays
- How to administer the Device Discovery Layer
- Administering DMP using the vxdmpadm utility
- Gathering and displaying I/O statistics
- Specifying the I/O policy
- Discovering and configuring newly added disk devices
- Dynamic Reconfiguration of devices
- Reconfiguring a LUN online that is under DMP control using the Dynamic Reconfiguration tool
- Manually reconfiguring a LUN online that is under DMP control
- Managing devices
- Displaying disk information
- Changing the disk device naming scheme
- Adding and removing disks
- Event monitoring
- Administering Dynamic Multi-Pathing
- Section IV. Administering Storage Foundation
- 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
- Administering sites and remote mirrors
- Section V. Optimizing I/O performance
- Veritas File System I/O
- Veritas Volume Manager I/O
- Managing application I/O workloads using maximum IOPS settings
- Section VI. Using Point-in-time copies
- Understanding point-in-time copy methods
- When to use point-in-time copies
- About Storage Foundation point-in-time copy technologies
- Volume-level snapshots
- Storage Checkpoints
- About FileSnaps
- About snapshot file systems
- Administering volume snapshots
- Traditional third-mirror break-off snapshots
- Full-sized instant snapshots
- Creating instant snapshots
- Adding an instant snap DCO and DCO volume
- Controlling instant snapshot synchronization
- Creating instant snapshots
- Cascaded snapshots
- Adding a version 0 DCO and DCO volume
- Administering Storage Checkpoints
- Storage Checkpoint administration
- Administering FileSnaps
- Administering snapshot file systems
- Understanding point-in-time copy methods
- Section VII. Optimizing storage with Storage Foundation
- Understanding storage optimization solutions in Storage Foundation
- Migrating data from thick storage to thin storage
- Maintaining Thin Storage with Thin Reclamation
- Reclamation of storage on thin reclamation arrays
- Identifying thin and thin reclamation LUNs
- Veritas InfoScale 4k sector device support solution
- Section VIII. Maximizing storage utilization
- Understanding storage tiering with SmartTier
- Creating and administering volume sets
- Multi-volume file systems
- Features implemented using multi-volume file system (MVFS) support
- Adding a volume to and removing a volume from a multi-volume file system
- Volume encapsulation
- Load balancing
- Administering SmartTier
- About SmartTier
- Placement classes
- Administering placement policies
- File placement policy rules
- Multiple criteria in file placement policy rule statements
- Using SmartTier with solid state disks
- Sub-file relocation
- Administering hot-relocation
- How hot-relocation works
- Moving relocated subdisks
- Deduplicating data
- Compressing files
- About compressing files
- Use cases for compressing files
- Section IX. Administering storage
- Managing volumes and disk groups
- Rules for determining the default disk group
- Moving volumes or disks
- Monitoring and controlling tasks
- Performing online relayout
- Adding a mirror to a volume
- Managing disk groups
- Disk group versions
- Displaying disk group information
- Importing a disk group
- Moving disk groups between systems
- Importing a disk group containing hardware cloned disks
- Handling conflicting configuration copies
- Destroying a disk group
- Backing up and restoring disk group configuration data
- Managing plexes and subdisks
- Decommissioning storage
- Rootability
- Encapsulating a disk
- Rootability
- Sample supported root disk layouts for encapsulation
- Encapsulating and mirroring the root disk
- Administering an encapsulated boot disk
- Quotas
- Using Veritas File System quotas
- File Change Log
- Managing volumes and disk groups
- Section X. Reference
- Appendix A. Reverse path name lookup
- Appendix B. Tunable parameters
- Tuning the VxFS file system
- Methods to change Dynamic Multi-Pathing tunable parameters
- Tunable parameters for VxVM
- Methods to change Veritas Volume Manager tunable parameters
- Appendix C. Command reference
Converting a plex into a snapshot plex
For a traditional, third-mirror break-off snapshot, you can convert an existing plex in a volume into a snapshot plex. Veritas recommends using the instant snapshot feature rather than converting a plex into a snapshot plex.
Note:
A plex cannot be converted into a snapshot plex for layered volumes or for any volume that has an associated instant snap DCO volume.
In some circumstances, you may find it more convenient to convert an existing plex in a volume into a snapshot plex rather than running vxassist snapstart. For example, you may want to do this if you are short of disk space for creating the snapshot plex and the volume that you want to snapshot contains more than two plexes.
The procedure can also be used to speed up the creation of a snapshot volume when a mirrored volume is created with more than two plexes and init=active is specified.
It is advisable to retain at least two plexes in a volume to maintain data redundancy.
To convert an existing plex into a snapshot plex for a volume on which Persistent FastResync is enabled, use the following command:
# vxplex [-g diskgroup] -o dcoplex=dcologplex convert \ state=SNAPDONE plex
dcologplex is the name of an existing DCO plex that is to be associated with the new snapshot plex. You can use the vxprint command to find out the name of the DCO volume.
For example, to make a snapshot plex from the plex trivol-03 in the 3-plex volume trivol, you would use the following command:
# vxplex -o dcoplex=trivol_dco-03 convert state=SNAPDONE \ trivol-03
Here the DCO plex trivol_dco_03 is specified as the DCO plex for the new snapshot plex.
To convert an existing plex into a snapshot plex in the SNAPDONE state for a volume on which Non-Persistent FastResync is enabled, use the following command:
# vxplex [-g diskgroup] convert state=SNAPDONE plex
A converted plex is in the SNAPDONE state, and can be used immediately to create a snapshot volume.
Note:
The last complete regular plex in a volume, an incomplete regular plex, or a dirty region logging (DRL) log plex cannot be converted into a snapshot plex.