Storage Foundation 8.0 Administrator's Guide - Windows
- Overview
- Setup and configuration
- Function overview
- About the client console for Storage Foundation
- Recommendations for caching-enabled disks
- Configure basic disks (Optional)
- About creating dynamic disk groups
- About creating dynamic volumes
- Set desired preferences
- Using the GUI to manage your storage
- Working with disks, partitions, and volumes
- Adding storage
- Disk tasks
- Remove a disk from the computer
- Veritas Disk ID (VDID)
- General Partition/Volume tasks
- Mount a volume at an empty folder (Drive path)
- Expand a dynamic volume
- Shrink a dynamic volume
- Basic disk and volume tasks
- Automatic discovery of SSD devices and manual classification as SSD
- Volume Manager space allocation is SSD aware
- Dealing with disk groups
- Disk groups overview
- Delete a dynamic disk group
- Detaching and attaching dynamic disks
- Importing and deporting dynamic disk groups
- Partitioned shared storage with private dynamic disk group protection
- Fast failover in clustered environments
- iSCSI SAN support
- Settings for monitoring objects
- Event monitoring and notification
- Event notification
- Configuring Automatic volume growth
- Standard features for adding fault tolerance
- Performance tuning
- FlashSnap
- FlashSnap components
- FastResync
- Snapshot commands
- Dynamic Disk Group Split and Join
- Dynamic disk group join
- Using Dynamic Disk Group Split and Join with a cluster on shared storage
- Dynamic Disk Group Split and Join troubleshooting tips
- Fast File Resync
- Volume Shadow Copy Service (VSS)
- Using the VSS snapshot wizards with Microsoft Exchange
- Using the VSS snapshot wizards with Enterprise Vault
- Using the VSS snapshot wizards with Microsoft SQL
- Copy on Write (COW)
- Using the VSS COW snapshot wizards with Microsoft Exchange
- Using the VSS COW snapshot wizards with Microsoft SQL
- Configuring data caching with SmartIO
- Typical deployment scenarios
- About cache area
- Configuring SmartIO
- Frequently asked questions about SmartIO
- Dynamic Multi-Pathing
- Configuring Cluster Volume Manager (CVM)
- Configuring a CVM cluster
- Administering CVM
- Access modes for cluster-shared volumes
- Storage disconnectivity and CVM disk detach policy
- Unconfiguring a CVM cluster
- Command shipping
- About I/O Fencing
- Administering site-aware allocation for campus clusters
- SFW for Hyper-V virtual machines
- Introduction to Storage Foundation solutions for Hyper-V environments
- Live migration support for SFW dynamic disk group
- Preparing the host machines
- Configuring the SFW storage
- Administering storage migration for SFW and Hyper-V virtual machine volumes
- Optional Storage Foundation features for Hyper-V environments
- Microsoft Failover Clustering support
- Configuring a quorum in a Microsoft Failover Cluster
- Implementing disaster recovery with Volume Replicator
- Troubleshooting and recovery
- Using disk and volume status information
- Resolving common problem situations
- Commands or procedures used in troubleshooting and recovery
- Rescan command
- Repair volume command for dynamic mirrored volumes
- Additional troubleshooting issues
- Disk issues
- Volume issues
- Disk group issues
- Connection issues
- Issues related to boot or restart
- Cluster issues
- Dynamic Multi-Pathing issues
- vxsnap issues
- Other issues
- CVM issues
- Appendix A. Command line interface
- Overview of the command line interface
- vxclustadm
- vxvol
- vxdg
- vxclus
- vxdisk
- vxassist
- vxassist (Windows-specific)
- vxsd
- vxedit
- vxdmpadm
- vxcbr
- vxsnap
- vxscrub
- sfcache
- Tuning SFW
- Appendix B. VDID details for arrays
Specifying load balancing settings for a disk
If a setting has not been specified for an individual disk, the disk assumes the same load balancing setting as the one used by the array. However, by using the Device Settings screen, you can change the load balancing option for an individual disk and make it different than the setting of the array.
DMP DSMs automatically set the load balancing to Fail Over Only (Active/Passive) for disks under SCSI-2 reservation. The Fail Over Only (Active/Passive) setting is always used on disks under SCSI-2 reservation and the system ignores other load balance settings that may be set.
Disks under SCSI-2 reservation are:
Disks that may be in a clustering environment.
Disks with Private Disk Group Protection.
To specify load balancing settings for a disk
- Open the DMP DSMs folder in the VEA console's tree view.
- Select the disk that has the load balancing settings you want to change.
Note that opening the Disks folder and clicking a disk that is under DMP DSMs control is an alternate way to select a disk.
- Make sure the DMP DSMs tab is selected in the right pane, right-click one of the displayed paths, and then select Device Settings from the path context menu.
- The Device Settings welcome screen appears. Click Next to continue.
- The Select Device Settings parameters screen appears.
Select one of the following load balancing options:
Round robin (Active/Active)
This option ensures that load balancing is used for data transfers to and from a disk. With this setting, DMP DSMs configures all paths to the disk as active and enables paths, each in turn, in a round-robin fashion for data transfer.
Dynamic Least Queue Depth
This option ensures that load balancing is used for data transfers to and from an array. With this setting, DMP DSMs configures all paths to the array as active and selects the path with the least number of I/O requests in its queue for a data transfer.
Balanced Path
This policy is designed to optimize the use of caching in disk drives and RAID controllers. The size of the cache depends on the characteristics of the particular hardware. Generally, disks and LUNs are logically divided into a number of regions or partitions. I/O to and from a given region is sent on only one of the active paths. Adjusting the region size to be compatible with the size of the cache is beneficial so that all the contiguous blocks of I/O to that region use the same active path. The value of the partition size can be changed by adjusting the value of the tunable parameter, Block Shift.
More details about this option are available.
Weighted Paths
This option ensures that load balancing is used for data transfers to and from an array. With this setting, DMP DSMs configures all paths to the array as active and selects the path with the lowest weight for data transfer. The user assigns weights to designate which path is favored. If two or more paths have the same weight and are the lowest weight of all paths, then these paths are used each in turn, in round-robin fashion, for the data transfer.
Round robin with Subset
This option ensures that load balancing is used for data transfers to and from an array. With this setting, DMP DSMs configures all paths to the array as active and uses a subset of paths each in turn, in round-robin fashion, for data transfer. The user specifies the subset of paths. The remaining paths are in standby mode.
Least Blocks
This option ensures that load balancing is used for data transfers to and from an array. With this setting, DMP DSMs configures all paths to the array as active and selects the path with the least number of blocks of I/O in its queue for data transfer.
Fail Over Only (Active/Passive)
This option has one primary path with the remaining path or paths on standby (backups) that are used when the current primary path fails. The primary path is the only path that is used to transfer data. This option does not provide load balancing among paths. DMP DSMs chooses a path to be the primary path. However, you may choose a specific path to be the primary path.
Click Next to continue.
- The Device Settings summary screen appears displaying the settings for the array. Review the settings and click Finish to apply the settings and exit the wizard.
For some load balance policies, such as round robin with Subset, additional specifications are required. The Array Settings wizard displays a screen before the summary screen to collect these specifications. Click Next after setting these specifications to continue to the summary screen.