分类：
2006-05-26 23:40:43
The command uses the trace facility to obtain a detailed picture of I/O activity during a time interval. Since it uses the trace facility, filemon can be run only by root or by a member of the system group.
In AIX Version 4, the filemon command is packaged as part of the Performance Toolbox for AIX. To determine whether filemon is available, use:
lslpp -lI perfagent.tools
If this package has been installed, filemon is available.
Tracing is started by the filemon command, optionally suspended with trcoff and resumed with trcon, and terminated with trcstop. As soon as tracing is terminated, filemon writes its report to stdout. The following sequence of commands gives a simple example of filemon use:
# filemon -o fm.test.out ; cp smit.log /dev/null ; trcstop
The report produced by this sequence, in an otherwise-idle system, was:
Wed Jan 12 11:28:25 1994
System: AIX alborz Node: 3 Machine: 000249573100
0.303 secs in measured interval
Cpu utilization: 55.3%
Most Active Segments
------------------------------------------------------------------------
#MBs #rpgs #wpgs segid segtype volume:inode
------------------------------------------------------------------------
0.1 26 0 0984 persistent /dev/hd1:25
0.0 1 0 34ba .indirect /dev/hd1:4
Most Active Logical Volumes
------------------------------------------------------------------------
util #rblk #wblk KB/s volume description
------------------------------------------------------------------------
0.66 216 0 357.0 /dev/hd1 /home
Most Active Physical Volumes
------------------------------------------------------------------------
util #rblk #wblk KB/s volume description
------------------------------------------------------------------------
0.65 216 0 357.0 /dev/hdisk1 320 MB SCSI
------------------------------------------------------------------------
Detailed VM Segment Stats (4096 byte pages)
------------------------------------------------------------------------
SEGMENT: 0984 segtype: persistent volume: /dev/hd1 inode: 25
segment flags: pers
reads: 26 (0 errs)
read times (msec): avg 45.644 min 9.115 max 101.388 sdev 33.045
read sequences: 3
read seq. lengths: avg 8.7 min 1 max 22 sdev 9.5
SEGMENT: 34ba segtype: .indirect volume: /dev/hd1 inode: 4
segment flags: pers jnld sys
reads: 1 (0 errs)
read times (msec): avg 16.375 min 16.375 max 16.375 sdev 0.000
read sequences: 1
read seq. lengths: avg 1.0 min 1 max 1 sdev 0.0
------------------------------------------------------------------------
Detailed Logical Volume Stats (512 byte blocks)
------------------------------------------------------------------------
VOLUME: /dev/hd1 description: /home
reads: 27 (0 errs)
read sizes (blks): avg 8.0 min 8 max 8 sdev 0.0
read times (msec): avg 44.316 min 8.907 max 101.112 sdev 32.893
read sequences: 12
read seq. lengths: avg 18.0 min 8 max 64 sdev 15.4
seeks: 12 (44.4%)
seek dist (blks): init 512
avg 312.0 min 8 max 1760 sdev 494.9
time to next req(msec): avg 8.085 min 0.012 max 64.877 sdev 17.383
throughput: 357.0 KB/sec
utilization: 0.66
------------------------------------------------------------------------
Detailed Physical Volume Stats (512 byte blocks)
------------------------------------------------------------------------
VOLUME: /dev/hdisk1 description: 320 MB SCSI
reads: 14 (0 errs)
read sizes (blks): avg 15.4 min 8 max 32 sdev 8.3
read times (msec): avg 13.989 min 5.667 max 25.369 sdev 5.608
read sequences: 12
read seq. lengths: avg 18.0 min 8 max 64 sdev 15.4
seeks: 12 (85.7%)
seek dist (blks): init 263168,
avg 312.0 min 8 max 1760 sdev 494.9
seek dist (cyls): init 399
avg 0.5 min 0 max 2 sdev 0.8
time to next req(msec): avg 27.302 min 3.313 max 64.856 sdev 22.295
throughput: 357.0 KB/sec
utilization: 0.65
The Most Active Segments report lists the most active files. To identify unknown files, you could translate the logical volume name, /dev/hd1, to the mount point of the file system, /home, and use the find command:
# find /home -inum 25 -print
which returns:
/home/waters/smit.log
Using filemon in systems with real workloads would result in much larger reports and might require more trace buffer space. filemon's space and CPU time consumption can degrade system performance to some extent. You should experiment with filemon on a nonproduction system before starting it in a production environment.
Note: Although filemon reports average, minimum, maximum, and standard deviation in its detailed-statistics sections, the results should not be used to develop confidence intervals or other formal statistical inferences. In general, the distribution of data points is neither random nor symmetrical.