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From: Gionatan Danti <g.danti@assyoma.it>
To: LVM general discussion and development <linux-lvm@redhat.com>
Cc: Ming-Hung Tsai <mingnus@gmail.com>
Subject: Re: [linux-lvm] How to check if thin volume or snapshot was ever activated
Date: Mon, 09 Aug 2021 10:33:31 +0200	[thread overview]
Message-ID: <d377f85bbd88932b36394b3ac62a5e6b@assyoma.it> (raw)
In-Reply-To: <CAAYit8S5RZ8wh0WAxWEyuJJ=ejVd+TOXqUDFLhMLDGNEGhhRjQ@mail.gmail.com>

Il 2021-08-09 05:53 Ming-Hung Tsai ha scritto:
> It sounds like you intend to keep snapshots that have been updated
> (written) since its creation, right?

True.

> The precise way might be checking the data mappings via thin_dump. An
> updated device has data mappings with timestamps greater than the
> device's creation time.

Interesting approach, thanks.

> Checking device activation might not meet what you need. An activated
> device might or might not receive any write, so you don't know whether
> a device has been updated by looking into its activation history.

Sure, but it can be a reasonable approximation before further 
inspection. Also, I wonder if dumping data mappings can be slow for big 
volumes.

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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  parent reply	other threads:[~2021-08-09  8:34 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-07 11:39 [linux-lvm] How to check if thin volume or snapshot was ever activated Gionatan Danti
2021-08-09  3:53 ` Ming-Hung Tsai
2021-08-09  4:16   ` Ming-Hung Tsai
2021-08-09  8:33   ` Gionatan Danti [this message]
     [not found]     ` <CAAYit8RWCA3W0y4vuZju6aZVSeu7e6SjErkZ1orLceJj0nhsvw@mail.gmail.com>
2021-08-10  8:46       ` Gionatan Danti

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