From: Alasdair G Kergon <agk@redhat.com>
To: Thanos Makatos <thanos.makatos@citrix.com>
Cc: "linux-lvm@redhat.com" <linux-lvm@redhat.com>
Subject: Re: [linux-lvm] deleted LV recovery: understanding metadata format and determining LV extents
Date: Sun, 11 Jan 2015 17:33:36 +0000 [thread overview]
Message-ID: <20150111173336.GA19834@agk-dp.fab.redhat.com> (raw)
In-Reply-To: <2368A3FCF9F7214298E53C823B0A48EC042ECF3F@AMSPEX01CL02.citrite.net>
On Sat, Jan 10, 2015 at 06:12:03PM +0000, Thanos Makatos wrote:
> Hi, I'm working on a case where a bunch of logical volumes were deleted but now we need them back. We have disabled archives and back ups in lvm.conf. They way I am trying to approach the problem is to examine LVM's metadata (the first MB of the block device) and determine whether the extents used by these logical volumes have been assigned to other logical volumes.
So start by looking at the contents of the metadata areas and see if they still
contain backups you can extract.
They are circular buffers so look for the seqno field which is incremented
each time the metadata is changed.
lvmdump -m can grab the metadata.
'pvck -v $device' contains the beginnings of code to extract the backups
Alasdair
prev parent reply other threads:[~2015-01-11 17:33 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-10 18:12 [linux-lvm] deleted LV recovery: understanding metadata format and determining LV extents Thanos Makatos
[not found] ` <1420926501.92697.YahooMailBasic@web181504.mail.ne1.yahoo.com>
2015-01-11 10:47 ` Thanos Makatos
2015-01-11 13:12 ` matthew patton
2015-01-11 17:33 ` Alasdair G Kergon [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20150111173336.GA19834@agk-dp.fab.redhat.com \
--to=agk@redhat.com \
--cc=linux-lvm@redhat.com \
--cc=thanos.makatos@citrix.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).