[linux-lvm] Fwd: LVM snapshots: guess *that's* not how it's done

[linux-lvm] Fwd: LVM snapshots: guess *that's* not how it's done

[Molle Bestefich]

Moderator requested 83kB of screenshots be scrapped.  Now it is.
(It's still in this original mail in the dm-devel archives.

---------- Forwarded message ----------
From: Molle Bestefich <molle.bestefich@gmail.com>
Date: Fri, 11 Nov 2005 14:16:22 +0100
Subject: LVM snapshots: guess *that's* not how it's done
To: dm-devel@redhat.com, linux-lvm@redhat.com

Good day,

I just bought a shiny big new box.
Contemplating using Xen + dm snapshots + unionfs + nbd to do various
fun things with it.
Since Fedora Core 4 has a couple of those things already in the
distro, I went with that.

I did this:
1. Install Fedora Core 4
2. Create a snapshot of the root volume with lvcreate

Seems the snapshotting did not go after plan - see attached screenshot....

Is that a serious bug in device-mapper or lvm, or is it just me that's
doing something wrong?

After the lvcreate, nothing works.  A couple things like 'df' does,
but otherwise there's dialogs complaining about missing ELF headers
and non-executable binary files no matter what I click or try to run.

This is the disk layout:

2x300GB SATA with 3 MD RAID1 partitions:
md0: 512MB ext3 --> /boot
md1: 8GB swap
md2: 250GB LVM --> VolGroup0

Dom0Vol: 20GB ext3 LV on VolGroup0
FC4_Install: 10GB snapshot LV of Dom0Vol

Both disks were burn-in tested twice before starting.

[linux-lvm] Re: LVM snapshots: guess *that's* not how it's done

[Molle Bestefich]

I wrote:
> Since Fedora Core 4 has a couple of those things already in the
> distro, I went with that.
>
> I did this:
> 1. Install Fedora Core 4
> 2. Create a snapshot of the root volume with lvcreate
>
> Seems the snapshotting did not go after plan - see attached screenshot....
>
> Is that a serious bug in device-mapper or lvm, or is it just me that's
> doing something wrong?
>
> After the lvcreate, nothing works.  A couple things like 'df' does,
> but otherwise there's dialogs complaining about missing ELF headers
> and non-executable binary files no matter what I click or try to run.

I was imagining that someone might have had a good way to get
information about what LVM and DM actually did wrong out of this
system.  Seems not.

If anybody wants to analyze this problem, the window of opportunity is closing.
If nobody pings me within 15 minutes, I'll nuke it and try EVMS :-).

Also, I'll be recommending LVM and DM to my family and friends.
Seems rock stable.  Not!!!  Haha...