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
Creating a mirrored volume
A mirrored volume provides data redundancy by containing more than one copy of its data. Each copy (or mirror) is stored on different disks from the original copy of the volume and from other mirrors. Mirroring a volume ensures that its data is not lost if a disk in one of its component mirrors fails.
A mirrored volume requires space to be available on at least as many disks in the disk group as the number of mirrors in the volume.
If you specify layout=mirror, vxassist determines the best layout for the mirrored volume. Because the advantages of the layouts are related to the size of the volume, vxassist selects the layout based on the size of the volume. For smaller volumes, vxassist uses the simpler mirrored concatenated (mirror-concat) layout. For larger volumes, vxassist uses the more complex concatenated mirror (concat-mirror) layout. The attribute stripe-mirror-col-split-trigger-pt controls the selection. Volumes that are smaller than stripe-mirror-col-split-trigger-pt are created as mirror-concat, and volumes that are larger are created as concat-mirror. By default, the attribute stripe-mirror-col-split-trigger-pt is set to one gigabyte. The value can be set in /etc/default/vxassist
. If there is a reason to implement a particular layout, you can specify layout=mirror-concat or layout=concat-mirror to implement the desired layout.
To create a new mirrored volume
- Create a new mirrored volume, using the following command:
# vxassist [-b] [-g diskgroup] make volume length \ layout=mirror [nmirror=number] [init=active]
Specify the -b option if you want to make the volume immediately available for use.
For example, to create the mirrored volume, volmir, in the disk group, mydg, use the following command:
# vxassist -b -g mydg make volmir 5g layout=mirror
The following example shows how to create a volume with 3 mirrors instead of the default of 2 mirrors:
# vxassist -b -g mydg make volmir 5g layout=mirror nmirror=3