From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mimecast-mx02.redhat.com (mimecast06.extmail.prod.ext.rdu2.redhat.com [10.11.55.22]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 769B42026D48 for ; Sat, 21 Nov 2020 08:22:10 +0000 (UTC) Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [207.211.31.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 32294185A7BC for ; Sat, 21 Nov 2020 08:22:10 +0000 (UTC) Received: by mail-io1-f48.google.com with SMTP id r1so12403391iob.13 for ; Sat, 21 Nov 2020 00:22:05 -0800 (PST) MIME-Version: 1.0 References: <20201120111433.GI1787072@localhost.localdomain> In-Reply-To: <20201120111433.GI1787072@localhost.localdomain> From: Sreyan Chakravarty Date: Sat, 21 Nov 2020 13:51:42 +0530 Message-ID: Content-Type: multipart/alternative; boundary="000000000000f8fafc05b499a7ab" Subject: Re: [linux-lvm] Unusually long boot times with LVM Snapshots Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: To: LVM general discussion and development --000000000000f8fafc05b499a7ab Content-Type: text/plain; charset="UTF-8" On Fri, Nov 20, 2020 at 4:45 PM Bryn M. Reeves wrote: > What type of snapshot are you using? LVM2 allows either "classic" CoW > snaps, > or the newer thin provisioned snapshots using the dm-thinp target. > > Classic snapshots are known to have very poor IO performance when multiple > snapshots of the same volume exist simultaneously (especially for write- > heavy workloads). > > Thin provisioned snapshots are not normally activated at boot time unless > they are explicitly requested (via dracut's rd.lvm.lv options) since they > have the skip activation flag set by default. > I tried thin snapshots, but what use are they if I can't use my system all together. Once my root logical volume was marked read only I could not revert it back to writable, after the snapshot was created. -- Regards, Sreyan Chakravarty --000000000000f8fafc05b499a7ab Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


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On Fri, Nov 20, 2020 at 4:45 PM Bryn = M. Reeves <bmr@redhat.com> wrot= e:
What type of = snapshot are you using? LVM2 allows either "classic" CoW snaps, or the newer thin provisioned snapshots using the dm-thinp target.

Classic snapshots are known to have very poor IO performance when multiple<= br> snapshots of the same volume exist simultaneously (especially for write- heavy workloads).

Thin provisioned snapshots are not normally activated at boot time unless they are explicitly requested (via dracut's rd.lvm.lv options) since they have the skip activation flag set by default.

I tried thin snapshots, but what use are they if I can't use my = system all together.

Once my root logical volume w= as marked read only I could not revert it back to writable, after the snaps= hot was created.=C2=A0

--
Regards,
Sreyan Chakravarty
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