How to Check File Access (sar -a) (System Administration Guide: Advanced Administration)

System Administration Guide: Advanced Administration

How to Check File Access (`sar -a`)

Display file access operation statistics with the sar -a command.

$ sar -a
SunOS venus 5.9 Generic sun4u    06/24/2001

00:00:00  iget/s namei/s dirbk/s
01:00:00       0       0       0
02:00:02       0       0       0
03:00:00       0       1       0
04:00:00       0       0       0
05:00:01       0       0       0
06:00:00       0       0       0

Average        0       1       0

The following table describes the operating system routines that are reported by the sar -a command.

Table 24–7 Output from the sar -a Command


Field Name	Description
`iget/s`	The number of requests made for inodes that were not in the directory name look-up cache (DNLC).
`namei/s`	The number of file system path searches per second. If `namei` does not find a directory name in the DNLC, it calls `iget` to get the inode for either a file or directory. Hence, most `igets` are the result of DNLC misses.
`dirbk/s`	The number of directory block reads issued per second.

The larger the reported values, the more time the kernel is spending to access user files. The amount of time reflects how heavily programs and applications are using the file systems. The -a option is helpful for viewing how disk-dependent an application is.