projects / blktrace.git / blame
| Commit | Line | Data |
|---|---|---|
| d0ca268b JA |
1 | Block IO Tracing |
| 2 | ---------------- | |
| 3 | ||
| 4 | Written by Jens Axboe <axboe@suse.de> (initial version and kernel support) and | |
| 5 | Alan D. Brunelle (threading and splitup into two seperate programs). | |
| 6 | ||
| 7 | ||
| c1bd9d09 JA |
8 | Requirements |
| 9 | ------------ | |
| 10 | ||
| 56c7d54d JA |
11 | You need to be running a 2.6.13-mm1 kernel with the blk-trace patch |
| 12 | included in this repository. If you forgot where you got it, the url is: | |
| c1bd9d09 JA |
13 | |
| 14 | rsync://rsync.kernel.org/pub/scm/linux/kernel/git/axboe/blktrace.git | |
| 15 | ||
| 6432fd98 JA |
16 | If you don't have git, you can get hourly snapshots from: |
| 17 | ||
| 18 | http://www.kernel.org/pub/linux/kernel/people/axboe/blktrace/ | |
| 19 | ||
| 20 | The snapshots include the full git object database as well. | |
| 21 | ||
| c1bd9d09 JA |
22 | |
| 23 | Usage | |
| 24 | ----- | |
| 25 | ||
| 152f6476 | 26 | % blktrace -d <dev> [-o <output> -a <trace> [-a <trace>] -k] |
| d0009925 JA |
27 | -a <trace> is one of: (use multiple -a options to get more) |
| 28 | READ | |
| 29 | WRITE | |
| 30 | BARRIER | |
| 31 | SYNC | |
| 32 | QUEUE | |
| 33 | REQUEUE | |
| 34 | ISSUE | |
| 35 | COMPLETE | |
| 36 | FS | |
| 37 | PC | |
| 152f6476 | 38 | -k Kill a currently running trace. |
| d0ca268b JA |
39 | --- run task to generate load to be traced --- |
| 40 | <SIGINT to kill> | |
| 41 | --- Generates: | |
| d0009925 | 42 | <output>_out.[0..ncpus] : Contains binary trace data |
| d0ca268b | 43 | |
| 152f6476 | 44 | % blkparse -i <input> [-o <output> -s] |
| d0ca268b | 45 | --- Generates: |
| 152f6476 JA |
46 | <output>.log : Contains formatted trace data, if |
| 47 | output logging is added with the -o option. Otherwise, the | |
| 48 | output is sent to stdout. If the -s option is used, in | |
| 49 | addition to per-CPU stats, per process stats are shown as well. | |
| c1bd9d09 JA |
50 | |
| 51 | ||
| d0009925 JA |
52 | If you want to do live tracing, you can pipe the data between blktrace |
| 53 | and blkparse: | |
| 54 | ||
| 55 | % blktrace -d <device> -o - | blkparse -i - | |
| 56 | ||
| 57 | This has a small risk of displaying some traces a little out of sync, since | |
| 58 | it will do batch sorts of input events. Similarly, you can do traces over | |
| 59 | the network with eg netcat: | |
| 60 | ||
| 61 | % blktrace -d /dev/sda -o - | netcat parsehost portno | |
| ebc37a0b | 62 | % netcat -l -p portno tracehost | blkparse -i - |
| d0009925 JA |
63 | |
| 64 | Which will send the traces from tracehost to parsehost over the network on | |
| 65 | the defined port number. | |
| 66 | ||
| 67 | ||
| 68 | 20050906, Jens Axboe <axboe@suse.de> | |
| c1bd9d09 | 69 |