Home > Veritas Storage Foundation™ File System Manual Pages
[ -r ] filename ...
qiostat reads statistics for the specified Quick I/O files and prints them to standard output. These statistics show I/O activity since the last time the file was opened from the Quick I/O interface, and are valid as long as the file remains open. Statistics reset to zero when the last file open from the Quick I/O interface is closed.
- number of read operations
- number of write operations
- number of blocks read
- number of blocks written
- average time spent on read operations in the interval
- average time spent on write operations in the interval
If the -i interval option is supplied, statistics are prefaced with a time stamp showing the current local time on the system.
If the -l option is specified, statistics are printed in two lines per object:
FILE NAME READ WRITE READ WRITE READ WRITE CREAD PREAD HIT RATIO cust0 2 1 8 4 5.0 10.0 2 1 50.0
The first line is the same as described above. The second line shows the caching statistics. Cached Quick I/O performs buffered reads and returns cached data (if available) without doing reads from the disk. Writes are performed as modified direct writes, that is, after the direct write to disk is scheduled, the file system updates the copy of data in cache (if it exists) with the same data being written to disk. In the column headings of the second line:
- CREADis the number of reads issued to cache
- PREADis the number of reads to the disk required because the data was not available in cache
- HIT RATIOis the percentage of the read requests that did not have to perform physical I/O and were satisfied from the cache (CREADs - PREADs / CREADs = HIT RATIO)
Display five sets of I/O statistics at 10 second intervals:
qiostat -i 10 -c 5 /mnt/oracle/\(**
Print cache statistics:
qiostat -l /mnt/oracle/\(**
Last updated: 01 April 2006
Copyright ©2009 Symantec Corporation
All rights reserved.