Home > Veritas Storage Foundation™ File System Manual Pages
QIOADMIN (1) |
User Commands |
mount_point can be either a prefix to a relative path name when qiotab is not specified, or can select a particular device in qiotab.
You can enable Cached Quick I/O on a file system by setting the tunable parameter qio_cache_enable=1 of vxtunefs (see the vxtunefs(1M) manual page). After setting the qio_cache_enable parameter, caching is enabled for all files in the file system. You can then turn caching off, or on again, on a per-file basis using qioadmin. The qio_cache_enable parameter is not persistent across mounts, returning to its default value when the file system is unmounted. You can make the qio_cache_enable parameter persistent across mounts by modifying the tunefstab file (see the tunefstab(4) manual page).
The qioadmin cache advisories operate only if Cached Quick I/O is enabled for the file system. If the qio_cache_enable flag is zero, Cached Quick I/O is OFF for all the files in that file system even if the individual file cache advisory for a file is ON. The per-file cache advisories are not persistent across mounts, returning to their default values when the file system is unmounted. You can use the qiotab file to make the cache advisory settings permanent.
For more information on how to use Cached Quick I/O, see the VERITAS File System Administrator's Guide and the VERITAS Storage Foundation for databases documentation.
device=block_device
Where block_device is the block device used to mount a file system.
The device= entry indicates the start of files belonging to a particular file system. All the files that follow the device= entry belong to the file system mounted on the specified device. The second device= entry delineates the end of files on one device and the start of files on another device.
The following qiotab example shows the list of files to cache in the file systems /database01 and /database02. For /database01, cust.dbf and system.dbf have Cached Quick I/O turned off, while cust.dbf has Cached Quick I/O turned on. For /database02, emp.dbf has Cached Quick I/O turned on, while history.dbf has Cached Quick I/O turned off.
..device=/dev/vgdb/database01device=/dev/vx/dsk/datadg/database01 cust.dbf,off system.dbf,off stk.dbf,ondevice=/dev/dsk/c3t0d0/database02 .. device=/dev/dsk/c3t0d0s4/database02 emp.dbf,on history.dbf,off
The VERITAS File System Administrator's Guide and the VERITAS Storage Foundation for databases documentation. have more detailed information.
Last updated: 1 Aug 2008
Copyright ©2009 Symantec Corporation
All rights reserved.