| Example of BCC tool bitesize.py |
| |
| The aim of this tool is to show I/O distribution for requested block sizes, by process name. |
| |
| # ./bitesize.py |
| Tracing... Hit Ctrl-C to end. |
| ^C |
| |
| Process Name: = 'kworker/u128:1' |
| Kbytes : count distribution |
| 0 -> 1 : 1 |******************** | |
| 2 -> 3 : 0 | | |
| 4 -> 7 : 2 |****************************************| |
| |
| Process Name: = 'bitesize.py' |
| Kbytes : count distribution |
| 0 -> 1 : 0 | | |
| 2 -> 3 : 0 | | |
| 4 -> 7 : 0 | | |
| 8 -> 15 : 0 | | |
| 16 -> 31 : 0 | | |
| 32 -> 63 : 0 | | |
| 64 -> 127 : 0 | | |
| 128 -> 255 : 1 |****************************************| |
| |
| Process Name: = 'dd' |
| Kbytes : count distribution |
| 0 -> 1 : 3 | | |
| 2 -> 3 : 0 | | |
| 4 -> 7 : 6 | | |
| 8 -> 15 : 0 | | |
| 16 -> 31 : 1 | | |
| 32 -> 63 : 1 | | |
| 64 -> 127 : 0 | | |
| 128 -> 255 : 0 | | |
| 256 -> 511 : 1 | | |
| 512 -> 1023 : 0 | | |
| 1024 -> 2047 : 488 |****************************************| |
| |
| Process Name: = 'jbd2/dm-1-8' |
| Kbytes : count distribution |
| 0 -> 1 : 0 | | |
| 2 -> 3 : 0 | | |
| 4 -> 7 : 1 |****************************************| |
| |
| Process Name: = 'cat' |
| Kbytes : count distribution |
| 0 -> 1 : 1 | | |
| 2 -> 3 : 0 | | |
| 4 -> 7 : 0 | | |
| 8 -> 15 : 0 | | |
| 16 -> 31 : 0 | | |
| 32 -> 63 : 1 | | |
| 64 -> 127 : 0 | | |
| 128 -> 255 : 0 | | |
| 256 -> 511 : 1924 |****************************************| |
| |
| Process Name: = 'ntpd' |
| Kbytes : count distribution |
| 0 -> 1 : 0 | | |
| 2 -> 3 : 0 | | |
| 4 -> 7 : 104 |****************************************| |
| |
| Process Name: = 'vmtoolsd' |
| Kbytes : count distribution |
| 0 -> 1 : 0 | | |
| 2 -> 3 : 0 | | |
| 4 -> 7 : 1 |****************************************| |
| |
| Process Name: = 'bash' |
| Kbytes : count distribution |
| 0 -> 1 : 0 | | |
| 2 -> 3 : 0 | | |
| 4 -> 7 : 0 | | |
| 8 -> 15 : 0 | | |
| 16 -> 31 : 2 |****************************************| |
| |
| Process Name: = 'jbd2/sdb-8' |
| Kbytes : count distribution |
| 0 -> 1 : 0 | | |
| 2 -> 3 : 0 | | |
| 4 -> 7 : 1 |****************************************| |
| 8 -> 15 : 0 | | |
| 16 -> 31 : 0 | | |
| 32 -> 63 : 1 |****************************************| |
| |
| We can see from above that there was a dd command being run which generated 488 IOPS between 1MB and 2MB, we can also see the |
| cat command generating 1924 IOPS between 256Kb and 512Kb. |
| |
| |
| See also systemtap version: |
| https://github.com/brendangregg/systemtap-lwtools/blob/master/disk/bitesize-nd.stp |