From: Xen <list@xenhideout.nl>
To: Gionatan Danti <g.danti@assyoma.it>
Cc: LVM, development <linux-lvm@redhat.com>,
Zdenek Kabelac <zkabelac@redhat.com>
Subject: Re: [linux-lvm] Snapshot behavior on classic LVM vs ThinLVM
Date: Sat, 22 Apr 2017 18:32:11 +0200 [thread overview]
Message-ID: <b1b73e21196be7c50daa098b2724880a@xenhideout.nl> (raw)
In-Reply-To: <e12f977563bfccf0a2a39aa3e53b9cf4@assyoma.it>
Gionatan Danti schreef op 22-04-2017 9:14:
> Il 14-04-2017 10:24 Zdenek Kabelac ha scritto:
>> However there are many different solutions for different problems -
>> and with current script execution - user may build his own solution -
>> i.e. call
>> 'dmsetup remove -f' for running thin volumes - so all instances get
>> 'error' device when pool is above some threshold setting (just like
>> old 'snapshot' invalidation worked) - this way user will just kill
>> thin volume user task, but will still keep thin-pool usable for easy
>> maintenance.
>>
>
> This is a very good idea - I tried it and it indeed works.
So a user script can execute dmsetup remove -f on the thin pool?
Oh no, for all volumes.
That is awesome, that means a errors=remount-ro mount will cause a
remount right?
> However, it is not very clear to me what is the best method to monitor
> the allocated space and trigger an appropriate user script (I
> understand that versione > .169 has %checkpoint scripts, but current
> RHEL 7.3 is on .166).
>
> I had the following ideas:
> 1) monitor the syslog for the "WARNING pool is dd.dd% full" message;
This is what my script is doing of course. It is a bit ugly and a bit
messy by now, but I could still clean it up :p.
However it does not follow syslog, but checks periodically. You can also
follow with -f.
It does not allow for user specified actions yet.
In that case it would fulfill the same purpose as > 169 only a bit more
poverly.
> One more thing: from device-mapper docs (and indeed as observerd in my
> tests), the "pool is dd.dd% full" message is raised one single time:
> if a message is raised, the pool is emptied and refilled, no new
> messages are generated. The only method I found to let the system
> re-generate the message is to deactiveate and reactivate the thin pool
> itself.
This is not my experience on LVM 111 from Debian.
For me new messages are generated when:
- the pool reaches any threshold again
- I remove and recreate any thin volume.
Because my system regenerates snapshots, I now get an email from my
script when the pool is > 80%, every day.
So if I keep the pool above 80%, every day at 0:00 I get an email about
it :p. Because syslog gets a new entry for it. This is why I know :p.
> And now the most burning question ... ;)
> Given that thin-pool is under monitor and never allowed to fill
> data/metadata space, as do you consider its overall stability vs
> classical thick LVM?
>
> Thanks.
next prev parent reply other threads:[~2017-04-22 16:32 UTC|newest]
Thread overview: 94+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-06 14:31 [linux-lvm] Snapshot behavior on classic LVM vs ThinLVM Gionatan Danti
2017-04-07 8:19 ` Mark Mielke
2017-04-07 9:12 ` Gionatan Danti
2017-04-07 13:50 ` L A Walsh
2017-04-07 16:33 ` Gionatan Danti
2017-04-13 12:59 ` Stuart Gathman
2017-04-13 13:52 ` Xen
2017-04-13 14:33 ` Zdenek Kabelac
2017-04-13 14:47 ` Xen
2017-04-13 15:29 ` Stuart Gathman
2017-04-13 15:43 ` Xen
2017-04-13 17:26 ` Stuart D. Gathman
2017-04-13 17:32 ` Stuart D. Gathman
2017-04-14 15:17 ` Xen
2017-04-14 7:27 ` Gionatan Danti
2017-04-14 7:23 ` Gionatan Danti
2017-04-14 15:23 ` Xen
2017-04-14 15:53 ` Gionatan Danti
2017-04-14 16:08 ` Stuart Gathman
2017-04-14 17:36 ` Xen
2017-04-14 18:59 ` Gionatan Danti
2017-04-14 19:20 ` Xen
2017-04-15 8:27 ` Xen
2017-04-15 23:35 ` Xen
2017-04-17 12:33 ` Xen
2017-04-15 21:22 ` Xen
2017-04-15 21:49 ` Xen
2017-04-15 21:48 ` Xen
2017-04-18 10:17 ` Zdenek Kabelac
2017-04-18 13:23 ` Gionatan Danti
2017-04-18 14:32 ` Stuart D. Gathman
2017-04-19 7:22 ` Xen
2017-04-07 22:24 ` Mark Mielke
2017-04-08 11:56 ` Gionatan Danti
2017-04-07 18:21 ` Tomas Dalebjörk
2017-04-13 10:20 ` Gionatan Danti
2017-04-13 12:41 ` Xen
2017-04-14 7:20 ` Gionatan Danti
2017-04-14 8:24 ` Zdenek Kabelac
2017-04-14 9:07 ` Gionatan Danti
2017-04-14 9:37 ` Zdenek Kabelac
2017-04-14 9:55 ` Gionatan Danti
2017-04-22 7:14 ` Gionatan Danti
2017-04-22 16:32 ` Xen [this message]
2017-04-22 20:58 ` Gionatan Danti
2017-04-22 21:17 ` Zdenek Kabelac
2017-04-23 5:29 ` Xen
2017-04-23 9:26 ` Zdenek Kabelac
2017-04-24 21:02 ` Xen
2017-04-24 21:59 ` Zdenek Kabelac
2017-04-26 7:26 ` Gionatan Danti
2017-04-26 7:42 ` Zdenek Kabelac
2017-04-26 8:10 ` Gionatan Danti
2017-04-26 11:23 ` Zdenek Kabelac
2017-04-26 13:37 ` Gionatan Danti
2017-04-26 14:33 ` Zdenek Kabelac
2017-04-26 16:37 ` Gionatan Danti
2017-04-26 18:32 ` Stuart Gathman
2017-04-26 19:24 ` Stuart Gathman
2017-05-02 11:00 ` Gionatan Danti
2017-05-12 13:02 ` Gionatan Danti
2017-05-12 13:42 ` Joe Thornber
2017-05-14 20:39 ` Gionatan Danti
2017-05-15 12:50 ` Zdenek Kabelac
2017-05-15 14:48 ` Gionatan Danti
2017-05-15 15:33 ` Zdenek Kabelac
2017-05-16 7:53 ` Gionatan Danti
2017-05-16 10:54 ` Zdenek Kabelac
2017-05-16 13:38 ` Gionatan Danti
2018-02-27 18:39 ` Xen
2018-02-28 9:26 ` Zdenek Kabelac
2018-02-28 19:07 ` Gionatan Danti
2018-02-28 21:43 ` Zdenek Kabelac
2018-03-01 7:14 ` Gionatan Danti
2018-03-01 8:31 ` Zdenek Kabelac
2018-03-01 9:43 ` Gianluca Cecchi
2018-03-01 11:10 ` Zdenek Kabelac
2018-03-01 9:52 ` Gionatan Danti
2018-03-01 11:23 ` Zdenek Kabelac
2018-03-01 12:48 ` Gionatan Danti
2018-03-01 16:00 ` Zdenek Kabelac
2018-03-01 16:26 ` Gionatan Danti
2018-03-03 18:32 ` Xen
2018-03-04 20:34 ` Zdenek Kabelac
2018-03-03 18:17 ` Xen
2018-03-04 20:53 ` Zdenek Kabelac
2018-03-05 9:42 ` Gionatan Danti
2018-03-05 10:18 ` Zdenek Kabelac
2018-03-05 14:27 ` Gionatan Danti
2018-03-03 17:52 ` Xen
2018-03-04 23:27 ` Zdenek Kabelac
2017-04-22 21:22 ` Zdenek Kabelac
2017-04-24 13:49 ` Gionatan Danti
2017-04-24 14:48 ` Zdenek Kabelac
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