From: Ryan Launchbury <ryan@magenta.tv>
To: Gionatan Danti <g.danti@assyoma.it>
Cc: LVM general discussion and development <linux-lvm@redhat.com>,
Zdenek Kabelac <zkabelac@redhat.com>
Subject: Re: [linux-lvm] Unable to un-cache logical volume when chunk size is over 1MiB
Date: Mon, 25 Jun 2018 18:20:54 +0100 [thread overview]
Message-ID: <CAG+RErkPfHbBGS9p90nu_mFErMsPQanPwEYz24DP5Yh3jQUBKg@mail.gmail.com> (raw)
In-Reply-To: <213e498ea447f141c7a975c13416281e@assyoma.it>
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Hi Gionatan,
The system with the issue is with writeback cache mode enabled.
Best regards,
Ryan
On Mon, 25 Jun 2018, 18:19 Gionatan Danti, <g.danti@assyoma.it> wrote:
> Il 24-06-2018 21:18 Ryan Launchbury ha scritto:
> > In testing, forcibly removing the cache, via editing the LVM config
> > file has caused extensive XFS filesystem corruption, even when backing
> > up the metadata first and restoring after the cache device is missing.
> > Any advice on how to safely uncache the volume would be massively
> > appreciated.
>
> It is my understanding that a writethrough cache should *never* have any
> data that are not on the backing volumes already.
> In other words, forcibly removing a writethough cache (ie: disconnetting
> the physical cache device) should not cause any harms to
> filesystem/data.
>
> Can you show the output of "dmsetup table"?
> Thanks.
>
> --
> Danti Gionatan
> Supporto Tecnico
> Assyoma S.r.l. - www.assyoma.it
> email: g.danti@assyoma.it - info@assyoma.it
> GPG public key ID: FF5F32A8
>
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next prev parent reply other threads:[~2018-06-25 17:21 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-20 9:18 [linux-lvm] Unable to un-cache logical volume when chunk size is over 1MiB Ryan Launchbury
2018-06-20 10:15 ` Zdenek Kabelac
2018-06-20 11:10 ` Ryan Launchbury
2018-06-22 18:13 ` Gionatan Danti
2018-06-22 19:22 ` Ryan Launchbury
2018-06-22 20:07 ` Zdenek Kabelac
2018-06-23 10:09 ` Gionatan Danti
2018-06-24 19:18 ` Ryan Launchbury
2018-06-25 17:19 ` Gionatan Danti
2018-06-25 17:20 ` Ryan Launchbury [this message]
2018-06-25 17:40 ` Gionatan Danti
2018-07-18 14:25 ` Ryan Launchbury
2018-07-18 14:58 ` Douglas Paul
2019-01-21 20:19 ` Zdenek Kabelac
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