From: Gionatan Danti <firstname.lastname@example.org> To: LVM general discussion and development <email@example.com> Cc: Sreyan Chakravarty <firstname.lastname@example.org> Subject: Re: [linux-lvm] What is the use of thin snapshots if the external origin cannot be set to writable ? Date: Mon, 23 Nov 2020 13:44:03 +0100 [thread overview] Message-ID: <email@example.com> (raw) In-Reply-To: <CAMaziXsY6vpQdD+QQzW_1Km+Ltf41tz0G1WG5xAUiMARFWHoyw@mail.gmail.com> Il 2020-11-21 04:10 Sreyan Chakravarty ha scritto: > I mean what is the point of creating a snapshot if I can't change my > original volume ? > > Is there some sort of resolution ? External thin snapshot are useful to share a common, read-only base (ie: a "gold-master" image) with different writable thin lvm overlay volumes. They can not be merged into external origin; otherwise, a single merge operation would invalidate *all* other thin snapshot relying on the same origin. Classical LVM snapshots are good for temporary, short-lived snapshots - basically taken for backup purpose only (and immediately removed after the backup completed). You should not use them for long-lived snapshots (otherwise you can see much lower performance and delayed boot). If you want to have long-lived snapshot you should use LVM thin snapshots. For root volumes, you have two choices: - use a thin lvm volume for root, which is a supported use case (but it will probably require a system reinstallation); - continue using your classical LVM as a immutable base and use a thin lvm with external snapshot to store all new writes. Regards. -- Danti Gionatan Supporto Tecnico Assyoma S.r.l. - www.assyoma.it email: firstname.lastname@example.org - email@example.com GPG public key ID: FF5F32A8
next prev parent reply other threads:[~2020-11-23 12:47 UTC|newest] Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-11-21 3:10 Sreyan Chakravarty 2020-11-23 12:44 ` Gionatan Danti [this message] 2020-11-23 13:04 ` Bryn M. Reeves 2020-11-24 11:59 ` Sreyan Chakravarty 2020-11-25 8:46 ` Sreyan Chakravarty 2020-11-25 12:38 ` Bryn M. Reeves 2020-11-25 15:31 ` Sreyan Chakravarty
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