Home > Veritas Storage Foundation™ File System Manual Pages

FIOSTAT (1)

User Commands

NAME
AVAILABILITY
SYNOPSIS
DESCRIPTION
KEYWORDS
OPTIONS
OUTPUT FORMAT
EXIT CODES
EXAMPLES
SEE ALSO

NAME

fiostat - VxFS file I/O statistics utility

AVAILABILITY

VRTSvxfs

SYNOPSIS

fiostat on [ -o offset] [ -l length] -n nfilerange pathname

fiostat off pathname

fiostat reset pathname

fiostat getconfig pathname

fiostat dump [ -i interval [ -c count] ] -r pathname

DESCRIPTION

The fiostat command prints and resets file and file range I/O statistics, turns on and off file range I/O statistics, and gets file range statistic configuration values. A file range is the portion of the file starting from the offset offset, and ending at the offset equal to offset plus length. The pathname parameter can be the pathname of a regular file or a QIO file. The file name extension ::cdev:vxfs: is required for a QIO file.

The fiostat command reads file-level I/O statistics for the specified file and prints the statistics to standard output. If file range statistics are turned on, fiostat reads and prints statistics for the file ranges. These statistics show I/O activity since the file's last close or since the previous statistics reset.

KEYWORDS

on: Turns on file range statistics for the specified file. If it is already on, current statistics are reset to zero and the configuration is set to the specified values.
off: Turns off file range statistics for the specified file. No action is taken if the file range statistics are already turned off.
reset: Resets statistics to zero.
getconfig: Prints the current configuration values, offset, length, and nfilerange, to standard output if file range statistics are turned on. When file range statistics are turned off, fiostat prints zeroes.
dump: Prints file statistics for the specified file to standard output. If file range statistics are turned on, fiostat prints the statistics to standard output.

OPTIONS

-c count

The fiostat command stops after printing statistics count times.

-i interval

Prints current I/O statistics every interval seconds.

-l length

Specifies the total length of file ranges in bytes. The length can be specified in kilobytes, megabytes, gigabytes, or terabytes by appending k, m, g, or t. The default length is the file's current size.

-o offset

Specifies the file offset in bytes where the first file range starts. The offset can be specified in kilobytes, megabytes, gigabytes, or terabytes by appending k, m, g, or t. The default offset is zero.

-n nfilerange

Specifies the number of file ranges to monitor. The number must be a non-zero value less than 1024. 1024 is the maximum number of file ranges allowed per file.

-r

Resets statistics to zero after each print.

OUTPUT FORMAT

I/O statistics are printed in a single line output record preceded by the file's name, the current local time on the system, the time when statistics were reset last, and two header lines. The output line consists of blank-separated fields for the object type (file or file range), and statistics on read and write operations:

Number of read operations

Number of write operations

Number of bytes read

Number of bytes written

Average time spent on read operations

Average time spent on write operations

File range statistics do not include average time spent on read and write operations.

The following is sample output of a file-level-only statistics dump:


File Name: /mnt/foo
Current time: Wed 28 Sep 2005 01:08:33 PM PDT
Reset time:   Wed 28 Sep 2005 01:06:33 PM PDT
FILE/SUBFILE OPERATIONS  BYTES       AVG TIME(ms)
             READ WRITE  READ WRITE  READ   WRITE

file         341  348   34926 35699  4.1    4.5

The following is sample output of a file and file range statistics dump:


File Name: /mnt/foo
Current time: Wed 28 Sep 2005 01:08:33 PM PDT
Reset time:   Wed 28 Sep 2005 01:06:33 PM PDT
FILE/SUBFILE OPERATIONS  BYTES       AVG TIME(ms)
             READ WRITE  READ WRITE  READ   WRITE

file         341  348   34926 35699  4.1    4.5
filerange1   27   24    2780  2434    
filerange2   27   28    2744  2813    
filerange3   27   28    2767  2808    
filerange4   25   26    2552  2634

If the -i interval option is supplied, statistics are prefaced with two time stamps showing the current local time on the system and when statistics were reset last.

The following is sample output of a file and file range statistics dump with -i 3 -c 3 specified:


File Name: /mnt/foo
FILE/SUBFILE OPERATIONS  BYTES       AVG TIME(ms)
             READ WRITE  READ WRITE  READ   WRITE

Current time: Wed 28 Sep 2005 12:56:40 PM PDT
Reset time:   Wed 28 Sep 2005 12:51:50 PM PDT
file         297  301   30426 30918  4.1    4.5   
filerange1   24   19    2503  1984    
filerange2   24   23    2447  2398    
filerange3   24   24    2439  2467    
filerange4   21   22    2122  2293 
Current time: Wed 28 Sep 2005 12:56:45 PM PDT
Reset time:   Wed 28 Sep 2005 12:51:50 PM PDT
file         322  324   33074 33746  4.1  4.5   
filerange1   26   22    2677  2204    
filerange2   26   26    2626  2664    
filerange3   26   26    2680  2695    
filerange4   23   24    2368  2490    
Current time: Wed 28 Sep 2005 12:56:50 PM PDT
Reset time:   Wed 28 Sep 2005 12:51:50 PM PDT
file         341  348   34926 35699  4.1    4.5
filerange1   27   24    2780  2434   
filerange2   27   28    2744  2813   
filerange3   27   28    2767  2808   
filerange4   25   26    2552  2634

EXIT CODES

fiostat exits with a non-zero status if the attempted operation fails. A non-zero exit code is not a complete indicator of the problems encountered, but rather denotes the first condition that prevented further execution of the command.

EXAMPLES

To display statistics for file /mnt/foo, which does not have file range statistics turned on:


# fiostat dump /mnt/foo

To turn on file range statistics for file /mnt/foo and monitor the file from offset 1024 to offset 1024+8129=9153 in 10 file ranges:


# fiostat on -o 1024 -l 8129 -n 10 /mnt/foo

To display statistics for file /mnt/foo 8 times at 5-second interval:


fiostat dump -i 5 -c 8 /mnt/foo

FIOSTAT (1)

Table of contents