InfoScale™ 9.0 Storage and Availability Management for DB2 Databases - AIX, Linux
- Section I. Storage Foundation High Availability (SFHA) management solutions for DB2 databases
- Overview of Storage Foundation for Databases
- About Veritas File System
- Overview of Storage Foundation for Databases
- Section II. Deploying DB2 with InfoScale products
- Deployment options for DB2 in a Storage Foundation environment
- Deploying DB2 with Storage Foundation
- Deploying DB2 in an off-host configuration with Storage Foundation
- Deploying DB2 with High Availability
- Deployment options for DB2 in a Storage Foundation environment
- Section III. Configuring Storage Foundation for Database (SFDB) tools
- Configuring and managing the Storage Foundation for Databases repository database
- Configuring the Storage Foundation for Databases (SFDB) tools repository
- Configuring authentication for Storage Foundation for Databases (SFDB) tools
- Configuring and managing the Storage Foundation for Databases repository database
- Section IV. Improving DB2 database performance
- About database accelerators
- Improving database performance with Quick I/O
- About Quick I/O
- Improving DB2 database performance with Veritas Concurrent I/O
- Section V. Using point-in-time copies
- Understanding point-in-time copy methods
- Volume-level snapshots
- Storage Checkpoints
- Considerations for DB2 point-in-time copies
- Administering third-mirror break-off snapshots
- Administering Storage Checkpoints
- Database Storage Checkpoints for recovery
- Backing up and restoring with Netbackup in an SFHA environment
- Understanding point-in-time copy methods
- Section VI. Optimizing storage costs for DB2
- Section VII. Storage Foundation for Databases administrative reference
- Storage Foundation for Databases command reference
- Tuning for Storage Foundation for Databases
- Troubleshooting SFDB tools
About obtaining volume I/O statistics
If your database is created on a single file system that is on a single volume, there is typically no need to monitor the volume I/O statistics. If your database is created on multiple file systems on multiple volumes, or the volume configurations have changed over time, it may be necessary to monitor the volume I/O statistics for the databases.
Use the vxstat command to access information about activity on volumes, plexes, subdisks, and disks under VxVM control, and to print summary statistics to the standard output. These statistics represent VxVM activity from the time the system initially booted or from the last time the counters were reset to zero. If no VxVM object name is specified, statistics from all volumes in the configuration database are reported. Use the -g option to specify the database disk group to report statistics for objects in that database disk group.
VxVM records the following I/O statistics:
count of operations
number of blocks transferred (one operation can involve more than one block)
average operation time (which reflects the total time through the VxVM interface and is not suitable for comparison against other statistics programs)
VxVM records the preceding three pieces of information for logical I/Os, including reads, writes, atomic copies, verified reads, verified writes, plex reads, and plex writes for each volume. VxVM also maintains other statistical data such as read failures, write failures, corrected read failures, corrected write failures, and so on. In addition to displaying volume statistics, the vxstat command is capable of displaying more detailed statistics on the components that form the volume. For detailed information on available options, refer to the vxstat(1M) manual page.
To reset the statistics information to zero, use the -r option. You can reset the statistics information for all objects or for only those objects that are specified. Resetting just prior to an operation makes it possible to measure the impact of that particular operation.
The following is an example of output produced using the vxstat command:
OPERATIONS BLOCKS AVG TIME(ms)
TYP NAME READ WRITE READ WRITE READ WRITE
vol log2 0 6312 0 79836 .0 0.2
vol db02 2892318 3399730 0283759 7852514 20.6 25.5
Additional information is available on how to use the vxstat output to identify volumes that have excessive activity and how to reorganize, change to a different layout, or move these volumes.
Additional volume statistics are available for RAID-5 configurations.
See the vxstat(1M) manual page.
See the "Performance Monitoring" section of the "Performance Monitoring and Tuning" chapter in the Storage Foundation Administrator's Guide.