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VXSTAT (1M) |
Maintenance Commands |
Only root users can reset statistics with the -r option of the vxstat utility. You do not need root access to execute the vxstat utility with other options to print statistics information.
The vxstat utility reads statistics from the volume device files in the directory /dev/vx/rdsk and prints them to standard output. These statistics represent volume, plex, subdisk, and disk activity since boot time. If no object operands are given, then statistics from all volumes in the configuration database are reported. object can be the name of a volume, plex, subdisk, disk, or cache object.
In a Veritas Volume Manager (VxVM) cluster environment, vxstat gathers the requested statistics from all nodes in the cluster, and reports the aggregate totals. You can specify a node list to indicate a subset of nodes from which to gather statistics.
- RD
- Percentage of reads in the total I/O.
- WR
- Non-first (non-allocating) writes in the total I/O.
- FW
- First (allocating) writes in the total I/O.
- RDTIME
- Moving average of time taken by reads in milliseconds.
- WRTIME
- Moving average of time taken by non-first writes in milliseconds.
- FWTIME
- Moving average of time taken by first writes in milliseconds.
- 0 | O
- Statistics for the VOL_R5_ZERO operation. Each operation represents one call to the VOL_R5_ZERO ioctl. The number of blocks is based on the number of zeroed blocks written to the array. The average time is the time taken to complete the entire ioctl operation.
- a
- Statistics on atomic copies performed (has meaning only for mirrored volumes). Displays the number of operations, number of blocks, and the average time spent per operation.
- b
- Displays the statistics on read-writeback mirror consistency recovery operations (has meaning only for mirrored volumes). Displays three fields: the number of read-writeback operations, the number of blocks involved in read-writeback operations, and the average time for completing a read-writeback operation. While in recovery mode, most read operations to a mirrored volume invoke read-writeback consistency recovery.
- c
- Statistics on corrected (fixed) read operations (has meaning only for mirrored or RAID-5 volumes). Displays the number of fixed read and write operations.
Note: Currently, only read operations are ever corrected, so the number of fixed writes will always be zero.
- C
- Statistics for the VOL_R5_RECOVER operation. Each operation count represents one call to the VOL_R5_RECOVER ioctl. The number of blocks represents the resulting number of blocks that were written to the missing column region as part of the data recovery. The read operations are not counted towards the total.
- e
- Displays statistics for extended copy operations on volumes including:
- OPS
- The number of extended copy operations performed.
- BLOCKS
- The number of blocks copied.
- AVG
- The average time taken per operation in milliseconds.
- f
- The number of failed read and write operations.
- F
- Statistics for full-stripe writes on RAID-5 volumes. The number of operations represents the number of write operations within a stripe that were conducted as a full-stripe write optimization. Full-stripe writes represent considerably less overhead than read-modify-writes in terms of overall I/O time, latency and CPU overhead. The total number of blocks represents the total size of the written data and the average time is the time taken for a full-stripe write operation. Since the I/O may be larger then a single stripe, more than one stripe operation may be seen for a single logical I/O request.
- M
- Read-modify-write statistics for RAID-5 volumes. Each operation represents a read-modify write operation performed within a stripe. I/O crossing a stripe boundary will be represented by more than a single read-modify write operation. The number of blocks counted represents only the size of the requested write. The read portion of the I/O can be derived.
- o
- Reads from source volumes that satisfy attempted reads from incomplete instant snapshots.
- p
- Pushed writes of original data to incomplete instant snapshots. These writes are caused by attempted writes to the source volumes.
- r
- Resync writes of original data to incomplete instant snapshots. These writes are caused by background synchronization operations rather than by pushed writes.
- R
- Reconstruct read operations for RAID-5 volumes. Each operation is a separate reconstruct read operation. A single stripe read or write operation can lead to numerous reconstruct read operations.
- s
- Statistics on read and write operations. Displays six fields: the number of read operations, the number of write operations, the number of blocks read, the number of blocks written, the average time spent on read operations in the interval, and the average time spent on write operations in the interval. These statistics are displayed as the default output format.
- S
- Statistics for the VOL_R5_RESYNC operation. Each operation count represents one call to the VOL_R5_RESYNC ioctl. The number of blocks represents the resulting number of blocks that were written to the parity regions as part of the resynchronization of parity. The read operations are not counted towards the total.
- v
- Statistics on verified reads and writes (has meaning only for mirrored volumes). Displays six fields: the number of verified read operations, the number of verified write operations, the number of blocks read, the number of blocks written, the average time spent on verified read operations in the interval, and the average time spent on verified write operations in the interval.
- V
- Statistics for the VOL_R5_VERIFY operation. Each operation count represents one call to the VOL_R5_VERIFY ioctl. The number of blocks represents the resulting number of blocks that were read as part of the RAID-5 stripes consistency verification.
- W
- Reconstruct write statistics for RAID-5 volumes. Each operation counted is for a reconstruct write operation performed as an optimization of a write operation within a stripe. The number of blocks counted represents the count of data blocks written not including parity or read operations.
Specify the -S option to display statistics for each interval grouped per second. Otherwise, the command displays the accumulated statistics for the entire time interval. With the -S option, the command generates scaled statistics outputs. The unit of the scaled output depends on how large the statistics value being printed is.
- INVALIDATIONS
- Number of pages whose contents have been invalidated for some reason.
- REPLACEMENTS
- Number of pages stolen to satisfy a new request.
- HITS
- Number of client requests that were satisfied from in-core pages.
- MISSES
- Number of client requests that could not be satisfied from the in-core pages, and which required the contents to be read from disk.
Units can be one of the following:
- b
- bytes
- k
- kilobytes
- m
- megabytes
- g
- gigabytes
If the -i interval option was supplied, then statistics will be prefaced with a time-stamp showing the current local time on the system.
See vxintro(1M) for a list of standard exit codes.
vxstat -s
To display statistics for the plexes and subdisks of a volume named blop, use the following:
vxstat -ps blop
To reset all statistics for a disk group named mydg, type the following command:
vxstat -g mydg -r
To display 5 sets of disk statistics at 10 second intervals, use the following:
vxstat -i 10 -c 5 -d
To display the volume statistics in disk group named mydg in microseconds use the following:
vxstat -g mydg -v -T
To display the per second disk statistics in disk group named mydg at 10 second intervals, use the following:
vxstat -g mydg -i 10 -S -d
To display the disk group statistics for all the disk groups on your system, use the following:
vxstat -o alldgs
To display the volume statistics in disk group named mydg in terms of megabytes, use the following:
vxstat -g mydg -v -u m
Last updated: 28 Jul 2003
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