>>>>> "Ben" == Ben England <bengland@xxxxxxxxxx> writes: Ben> John, thanks for reply, comments inline... Ben> ----- Original Message ----- >> From: "John Stoffel" <john@xxxxxxxxxxx> >> To: "Ben England" <bengland@xxxxxxxxxx> >> Cc: dm-devel@xxxxxxxxxx >> Sent: Friday, May 27, 2016 11:15:51 AM >> Subject: Re: getting feedback on dm-cache statistics tool >> >> Ben> I have a git repo containing a tool I wrote to look at dm-cache Ben> statistics, not the raw counters in "dmsetup status" but derived Ben> values that are more directly useful to system administrators and Ben> developers that want to see whether dm-cache is doing what they Ben> want it to. https://github.com/bengland2/dmcache-stat >> Ben> Any feedback on this? Anything missing? I don't mind adding or Ben> taking pull requests. If some other tool can provide the same Ben> functionality within RHEL then I'm happy to use that. >> >> I'm using Debian Jessie on x86_64 running kernel 4.4.0-rc7 (self >> compiled) and it's dying with an error: >> Ben> I don't have a Debian system handy, can you do "dmsetup status" Ben> on it and mail me the log so I know what the format difference Ben> is? It's mostly because I think I have bad UUIDs on my LVM volumes, because I've basically just upgraded this system for the past six years, without building new volumes/LVMs. Here's the output though: > sudo dmsetup status [sudo] password for john: The UUID "LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wVLvpBly2guNYp3XUqTVCgGCHequQOBEf9" should be mangled b. The UUID "LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wVkuRxXnQASgLcdsdFmK9OviYa88Q6buOU" should be mangled b. quad-swap_1: 0 15622144 linear The UUID "LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wVM32OGu9FYyW2J5u8Q1zSNh826zw6BnFX" should be mangled b. quad-root: 0 78118912 linear The UUID "LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wVabjo7c4R5l6twigsqqfc55LVN6XVag4W-cdata" should be man. The UUID "LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wVIWMZ8hjG32sj1LIdQja6QWB4OWkUvUCl" should be mangled b. bacula-backups: 0 5857345536 linear The UUID "LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wVkOhak3U4uF82eWXH5JY1F3VhHzMHYV8c-cmeta" should be man. The UUID "LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wVR1c11WDl2e86Ko9OmuWYRIUNXExHQnX1" should be mangled b. The UUID "LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wVvdF6NWzpggiPLD202jpru363Z5LfB5Lo" should be mangled b. The UUID "LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wV40890zsM04q5zMIs0qdeCDfG9fc9FwbF" should be mangled b. The UUID "LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wVrdBEgHTcrXLHDWNrbFotKPeLt2TfbRVo" should be mangled b. The UUID "LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wVi37feovUsvWbysOk8PI2bbdjqokieGx2-cdata" should be man. quad-var: 0 39059456 linear quad-var: 39059456 83886080 linear The UUID "LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wVnp1To0klyekIS85gueDeq2EsYg5Osj44" should be mangled b. The UUID "LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wVas2sZsZM8mw0VXDgx03ryaq351RUEL4j-cmeta" should be man. bacula-incrs: 0 5662310400 linear The UUID "LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wVbbcg3pVFZyDngdRLS4aECbc571Lyb5MI" should be mangled b. Command failed >> > sudo ./dmcache_stat.py 10 0 >> volname, size(GiB), policy, mode >> The UUID >> "LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wVLvpBly2guNYp3XUqTVCgGCHequQOBEf9" >> should be mangled b. >> The UUID >> "LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wVkuRxXnQASgLcdsdFmK9OviYa88Q6buOU" >> should be mangled b. >> The UUID >> "LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wVM32OGu9FYyW2J5u8Q1zSNh826zw6BnFX" >> should be mangled b. >> The UUID >> "LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wVabjo7c4R5l6twigsqqfc55LVN6XVag4W-cdata" >> should be man. >> The UUID >> "LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wVIWMZ8hjG32sj1LIdQja6QWB4OWkUvUCl" >> should be mangled b. >> The UUID >> "LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wVkOhak3U4uF82eWXH5JY1F3VhHzMHYV8c-cmeta" >> should be man. >> The UUID >> "LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wVR1c11WDl2e86Ko9OmuWYRIUNXExHQnX1" >> should be mangled b. >> The UUID >> "LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wVvdF6NWzpggiPLD202jpru363Z5LfB5Lo" >> should be mangled b. >> The UUID >> "LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wV40890zsM04q5zMIs0qdeCDfG9fc9FwbF" >> should be mangled b. >> The UUID >> "LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wVrdBEgHTcrXLHDWNrbFotKPeLt2TfbRVo" >> should be mangled b. >> The UUID >> "LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wVi37feovUsvWbysOk8PI2bbdjqokieGx2-cdata" >> should be man. >> The UUID >> "LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wVnp1To0klyekIS85gueDeq2EsYg5Osj44" >> should be mangled b. >> The UUID >> "LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wVas2sZsZM8mw0VXDgx03ryaq351RUEL4j-cmeta" >> should be man. >> The UUID >> "LVM-HWDbRMPFL85!mVbEi4wru5#G7YfWK3wVbbcg3pVFZyDngdRLS4aECbc571Lyb5MI" >> should be mangled b. >> Command failed >> Traceback (most recent call last): >> File "./dmcache_stat.py", line 198, in <module> >> s2 = poll_dmcache() >> File "./dmcache_stat.py", line 172, in poll_dmcache >> dmsetup_out = subprocess.check_output(['dmsetup', 'status']) >> File "/usr/lib/python2.7/subprocess.py", line 573, in check_output >> raise CalledProcessError(retcode, cmd, output=output) >> subprocess.CalledProcessError: Command '['dmsetup', 'status']' returned >> non-zero exit status 1 >> >> >> But this is partly because my UUIDs aren't being handled properly and I've >> been loathe to follow the process for rebuilding them because I'm scared. >> And it's my main fileserver. Maybe this weekend if I have time. >> >> >> The other comment is that the usage should be more like: >> >> dmcache-stat <interval> [<count>] >> Ben> That's quite reasonable and easily done - will get to it soon. >> where if you don't provide the count, it defaults to going forever, like >> iostat/vmstat, etc. >> >> And now that I think of it, I'm using lvmcache, not dmcache or bcache... Ben> I thought LVMcache was just a way of persisting dm-cache volumes Ben> across reboots and managing them with LVM, not functionally Ben> different underneath. Could be, I'm vague on the details. And thinking about it, it must be dmcache being used by lvmcache, because I distinctly choose to NOT use bcache due to it's lack of flexibility. I'm really looking for some way to quantify the speedup of lvmcache/dmcache on my setup. This weekend it's time to fix the UUIDs though. John -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
