projects / blktrace.git / blame
| Commit | Line | Data |
|---|---|---|
| d0ca268b JA |
1 | Block IO Tracing |
| 2 | ---------------- | |
| 3 | ||
| e7c9f3ff NS |
4 | Written by Jens Axboe <axboe@suse.de> (initial version and kernel support), |
| 5 | Alan D. Brunelle (threading and splitup into two seperate programs), | |
| 6 | Nathan Scott <nathans@sgi.com> (bug fixes, process names, multiple devices) | |
| d0ca268b JA |
7 | |
| 8 | ||
| c1bd9d09 JA |
9 | Requirements |
| 10 | ------------ | |
| 11 | ||
| 6d1b9657 | 12 | You need to be running a 2.6.14-rc1 kernel or newer, with the blk-trace patch |
| 56c7d54d | 13 | included in this repository. If you forgot where you got it, the url is: |
| c1bd9d09 JA |
14 | |
| 15 | rsync://rsync.kernel.org/pub/scm/linux/kernel/git/axboe/blktrace.git | |
| 16 | ||
| 6432fd98 JA |
17 | If you don't have git, you can get hourly snapshots from: |
| 18 | ||
| 19 | http://www.kernel.org/pub/linux/kernel/people/axboe/blktrace/ | |
| 20 | ||
| 21 | The snapshots include the full git object database as well. | |
| 22 | ||
| c1bd9d09 JA |
23 | |
| 24 | Usage | |
| 25 | ----- | |
| 26 | ||
| 152f6476 | 27 | % blktrace -d <dev> [-o <output> -a <trace> [-a <trace>] -k] |
| d0009925 JA |
28 | -a <trace> is one of: (use multiple -a options to get more) |
| 29 | READ | |
| 30 | WRITE | |
| 31 | BARRIER | |
| 32 | SYNC | |
| 33 | QUEUE | |
| 34 | REQUEUE | |
| 35 | ISSUE | |
| 36 | COMPLETE | |
| 37 | FS | |
| 38 | PC | |
| 152f6476 | 39 | -k Kill a currently running trace. |
| d0ca268b JA |
40 | --- run task to generate load to be traced --- |
| 41 | <SIGINT to kill> | |
| 42 | --- Generates: | |
| d0009925 | 43 | <output>_out.[0..ncpus] : Contains binary trace data |
| d0ca268b | 44 | |
| 32fb90fe | 45 | % blkparse -i <input> [-o <output> -s -t] |
| d0ca268b | 46 | --- Generates: |
| 152f6476 JA |
47 | <output>.log : Contains formatted trace data, if |
| 48 | output logging is added with the -o option. Otherwise, the | |
| 49 | output is sent to stdout. If the -s option is used, in | |
| 50 | addition to per-CPU stats, per process stats are shown as well. | |
| 32fb90fe JA |
51 | The -t option will provide individual io statistics, displaying |
| 52 | things like completion time, queueing time, etc. | |
| c1bd9d09 JA |
53 | |
| 54 | ||
| d0009925 JA |
55 | If you want to do live tracing, you can pipe the data between blktrace |
| 56 | and blkparse: | |
| 57 | ||
| 58 | % blktrace -d <device> -o - | blkparse -i - | |
| 59 | ||
| 60 | This has a small risk of displaying some traces a little out of sync, since | |
| 61 | it will do batch sorts of input events. Similarly, you can do traces over | |
| 62 | the network with eg netcat: | |
| 63 | ||
| 64 | % blktrace -d /dev/sda -o - | netcat parsehost portno | |
| ebc37a0b | 65 | % netcat -l -p portno tracehost | blkparse -i - |
| d0009925 JA |
66 | |
| 67 | Which will send the traces from tracehost to parsehost over the network on | |
| 68 | the defined port number. | |
| 69 | ||
| 70 | ||
| 71 | 20050906, Jens Axboe <axboe@suse.de> | |
| c1bd9d09 | 72 |