From: Gionatan Danti <g.danti@assyoma.it>
To: Zdenek Kabelac <zkabelac@redhat.com>
Cc: matthew, LVM general discussion and development <linux-lvm@redhat.com>
Subject: Re: [linux-lvm] Reserve space for specific thin logical volumes
Date: Wed, 13 Sep 2017 10:28:20 +0200 [thread overview]
Message-ID: <738b359eccce111fb8c81733276b9845@assyoma.it> (raw)
In-Reply-To: <b0d6b9a1-19fa-5e88-e031-d30d7386dfe8@redhat.com>
Il 13-09-2017 10:15 Zdenek Kabelac ha scritto:
> Ohh this is pretty major constrain ;)
Sure :p
Sorry for not explicitly stating that before.
>
> But as pointed out multiple times - with scripting around various
> fullness moments of thin-pool - several different actions can be
> programmed around,
> starting from fstrim, ending with plain erase of unneeded snapshot.
> (Maybe erasing unneeded files....)
>
> To get most secure application - such app should actually avoid using
> page-cache (using direct-io) in such case you are always guaranteed
> to get exact error at the exact time (i.e. even without journaled
> mounting option for ext4....)
>
>
True, but pagecache exists for a reason. Anyway, this is not anything
you can "fix" in device mapper/lvm, I 100% agree with that.
> Partially this might get solved in 'some' cases with fully provisioned
> thinLVs within thin-pool...
>
> What comes to my mind as possible supporting solution is -
> adding possible enhancement on LVM2 side could be 'forcible' removal
> of running volumes (aka lvm2 equivalent of 'dmsetup remove --force')
>
> ATM lvm2 prevents you to remove 'running/mounted' volumes.
>
> I can well imagine LVM will let you forcible replace such LV with
> error target - so instead of thinLV - you will have single 'error'
> target snapshot - which could be possibly even auto-cleaned once the
> volume use-count drops bellow 0 (lvmpolld/dmeventd monitoring
> whatever...)
>
> (Of course - we are not solving what happens to application
> using/running out of such error target - hopefully something not
> completely bad....)
>
> This way - you get very 'powerful' weapon to be used in those
> 'scriplets'
> so you can drop uneeded volumes ANYTIME you need to and reclaim its
> resources...
>
This would be *really* great. I played with dm-setup remove/error target
and, while working, it often freezed LVM.
An integrated forced volume removal/swith to error target would be
great.
Thank.
--
Danti Gionatan
Supporto Tecnico
Assyoma S.r.l. - www.assyoma.it
email: g.danti@assyoma.it - info@assyoma.it
GPG public key ID: FF5F32A8
next prev parent reply other threads:[~2017-09-13 8:28 UTC|newest]
Thread overview: 90+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1575245610.821680.1505258554456.ref@mail.yahoo.com>
2017-09-12 23:22 ` [linux-lvm] Reserve space for specific thin logical volumes matthew patton
2017-09-13 7:53 ` Gionatan Danti
2017-09-13 8:15 ` Zdenek Kabelac
2017-09-13 8:28 ` Gionatan Danti [this message]
2017-09-13 8:44 ` Zdenek Kabelac
2017-09-13 10:46 ` Gionatan Danti
[not found] <914479528.2618507.1505463313888.ref@mail.yahoo.com>
2017-09-15 8:15 ` matthew patton
2017-09-15 10:01 ` Zdenek Kabelac
2017-09-15 18:35 ` Xen
[not found] <498090067.1559855.1505338608244.ref@mail.yahoo.com>
2017-09-13 21:36 ` matthew patton
[not found] <1771452279.913055.1505269434212.ref@mail.yahoo.com>
2017-09-13 2:23 ` matthew patton
2017-09-13 7:25 ` Zdenek Kabelac
[not found] <57374453.843393.1505261050977.ref@mail.yahoo.com>
2017-09-13 0:04 ` matthew patton
2017-09-13 7:10 ` Zdenek Kabelac
[not found] <691633892.829188.1505258696384.ref@mail.yahoo.com>
2017-09-12 23:24 ` matthew patton
[not found] <418002318.647314.1505245480415.ref@mail.yahoo.com>
[not found] ` <418002318.647314.1505245480415@mail.yahoo.com>
2017-09-12 21:36 ` Gionatan Danti
2017-09-12 22:16 ` Zdenek Kabelac
2017-09-12 22:41 ` Gionatan Danti
2017-09-12 23:02 ` Zdenek Kabelac
2017-09-12 23:15 ` Gionatan Danti
2017-09-12 23:31 ` Zdenek Kabelac
2017-09-13 8:21 ` Gionatan Danti
[not found] <1806055156.426333.1505228581063.ref@mail.yahoo.com>
2017-09-12 15:03 ` matthew patton
2017-09-12 17:09 ` Gionatan Danti
2017-09-12 22:41 ` Zdenek Kabelac
2017-09-12 22:55 ` Gionatan Danti
2017-09-12 23:11 ` Zdenek Kabelac
[not found] <832949972.1610294.1505170613541.ref@mail.yahoo.com>
2017-09-11 22:56 ` matthew patton
2017-09-12 5:28 ` Gionatan Danti
2017-09-08 10:35 Gionatan Danti
2017-09-08 11:06 ` Xen
2017-09-09 22:04 ` Gionatan Danti
2017-09-11 10:35 ` Zdenek Kabelac
2017-09-11 10:55 ` Xen
2017-09-11 11:20 ` Zdenek Kabelac
2017-09-11 12:06 ` Xen
2017-09-11 12:45 ` Xen
2017-09-11 13:11 ` Zdenek Kabelac
2017-09-11 13:46 ` Xen
2017-09-12 11:46 ` Zdenek Kabelac
2017-09-12 12:37 ` Xen
2017-09-12 14:37 ` Zdenek Kabelac
2017-09-12 16:44 ` Xen
2017-09-12 17:14 ` Gionatan Danti
2017-09-12 21:57 ` Zdenek Kabelac
2017-09-13 17:41 ` Xen
2017-09-13 19:17 ` Zdenek Kabelac
2017-09-14 3:19 ` Xen
2017-09-12 17:00 ` Gionatan Danti
2017-09-12 23:25 ` Brassow Jonathan
2017-09-13 8:15 ` Gionatan Danti
2017-09-13 8:33 ` Zdenek Kabelac
2017-09-13 18:43 ` Xen
2017-09-13 19:35 ` Zdenek Kabelac
2017-09-14 5:59 ` Xen
2017-09-14 19:05 ` Zdenek Kabelac
2017-09-15 2:06 ` Brassow Jonathan
2017-09-15 6:02 ` Gionatan Danti
2017-09-15 8:37 ` Xen
2017-09-15 7:34 ` Xen
2017-09-15 9:22 ` Zdenek Kabelac
2017-09-16 22:33 ` Xen
2017-09-17 6:31 ` Xen
2017-09-17 7:10 ` Xen
2017-09-18 19:20 ` Gionatan Danti
2017-09-20 13:05 ` Xen
2017-09-21 9:49 ` Zdenek Kabelac
2017-09-21 10:22 ` Xen
2017-09-21 13:02 ` Zdenek Kabelac
2017-09-21 14:49 ` Xen
2017-09-21 20:32 ` Zdenek Kabelac
2017-09-18 8:56 ` Zdenek Kabelac
2017-09-11 14:00 ` Xen
2017-09-11 17:34 ` Zdenek Kabelac
2017-09-11 15:31 ` Eric Ren
2017-09-11 15:52 ` Zdenek Kabelac
2017-09-11 21:35 ` Eric Ren
2017-09-11 17:41 ` David Teigland
2017-09-11 21:08 ` Eric Ren
2017-09-11 16:55 ` David Teigland
2017-09-11 17:43 ` Zdenek Kabelac
2017-09-11 21:59 ` Gionatan Danti
2017-09-12 11:01 ` Zdenek Kabelac
2017-09-12 11:34 ` Gionatan Danti
2017-09-12 12:03 ` Zdenek Kabelac
2017-09-12 12:47 ` Xen
2017-09-12 13:51 ` pattonme
2017-09-12 14:57 ` Zdenek Kabelac
2017-09-12 16:49 ` Xen
2017-09-12 16:57 ` Gionatan Danti
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