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
Importing a set of cloned disks with tags
If you copy the same set of disks more than once, each disk has multiple clone disks. VxVM recognizes the difference between the source disks and the clone disks, but cannot determine which clone disks represent a consistent set of data. For example, if you take several hardware snapshots at different times, one set of cloned disks represents each snapshot point in time.
If you attempt to import the cloned disks of the disk group (using the -o useclonedev option), the import operation fails if VxVM detects multiple clones of the same disks. This behavior prevents import of an inconsistent set of disks. For example, a mix of snapshot disks from different points in time.
If multiple clone sets exist, you must indicate to VxVM which clone disks to select for import. Identify the disks that make up a consistent set and assign VxVM tags to the disks. Then, you can import the cloned disks with the specified tag.
To import a set of cloned disks with tags
- Identify which disks need to be imported together as a set.
# vxdisk -o alldgs list DEVICE TYPE DISK GROUP STATUS EMC0_4 auto:cdsdisk mydg01 mydg online EMC0_6 auto:cdsdisk mydg02 mydg online EMC0_8 auto:cdsdisk - (mydg) online udid_mismatch EMC0_15 auto:cdsdisk - (mydg) online udid_mismatch EMC0_18 auto:cdsdisk - (mydg) online udid_mismatch EMC0_24 auto:cdsdisk - (mydg) online udid_mismatch
- If the disks are not already tagged, use the following command to tag all the disks in the disk group that are to be imported:
# vxdisk [-g diskgroup ] settag tagname disk ...
where tagname is a string of up to 128 characters, not including spaces or tabs.
For example, suppose the udid_mismatch disks represent two different point-in-time snapshots. To distinguish between the snapshots, you can tag the disks as follows:
# vxdisk settag snaptag1=snap1 EMC0_8 EMC0_15
# vxdisk settag snaptag2=snap2 EMC0_18 EMC0_24
See the vxdisk(1M) manual page.
- To check which disks are tagged, use the vxdisk listtag command:
# vxdisk listtag DEVICE NAME VALUE EMC0_8 snaptag1 snap1 EMC0_15 snaptag1 snap1 EMC0_18 snaptag2 snap2 EMC0_24 snaptag2 snap2
- To import the cloned disks that are tagged as snaptag1, update the UDIDs. You must assign a disk group name other than mydg, because the mydg disk group is already imported.
# vxdg -n bcvdg -o useclonedev=on -o tag=snaptag1 -o updateid \ import mydg # vxdisk -o alldgs list DEVICE TYPE DISK GROUP STATUS EMC0_4 auto:cdsdisk mydg01 mydg online EMC0_6 auto:cdsdisk mydg02 mydg online EMC0_8 auto:cdsdisk mydg01 bcvdg online EMC0_15 auto:cdsdisk mydg02 bcvdg online EMC0_18 auto:cdsdisk - (mydg) online udid_mismatch EMC0_24 auto:cdsdisk - (mydg) online udid_mismatch
The cloned disks EMC0_18 and EMC0_24 are not imported, since they do not have the snaptag1.
The state of the imported cloned disks has changed from online udid_mismatch to online. The disks are now in a new disk group, so VxVM removes the clone_disk flag.
See the vxdg(1M) manual page.