On 9/30/2012 4:28 PM, Phil Turmel wrote:
On 09/30/2012 03:25 PM, EJ Vincent wrote:
On 9/30/2012 3:22 PM, Mathias Burén wrote:
Can't you just boot off an older Ubuntu USB, install mdadm and scan /
assemble, see the device order?
Hi Mathias,
I'm under the impression that damage to the metadata has already been
done by 12.04, making a recovery from an older version of Ubuntu
(10.04), impossible. Is this line of thinking, flawed?
Your impression is correct. Permanent damage to the metadata was done.
You *must* re-create your array.
However, you *cannot* use your new version of mdadm, as it will get the
data offset wrong. Your first report showed a data offset of 272.
Newer versions of mdadm default to 2048. You *must* perform all of your
"mdadm --create --assume-clean" permutations with 10.04.
Do you have *any* dmesg output from the old system? Or dmesg from the
very first boot under 12.04? That might have enough information to
shorten your search.
In the future, you should record your setup by saving the output of
"mdadm -D" on each array, "mdadm -E" on each member device, and the
output of "ls -l /dev/disk/by-id/"
Or try my documentation script "lsdrv". [1]
HTH,
Phil
[1] http://github.com/pturmel/lsdrv
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Hi Phil,
Unfortunately I don't have any dmesg log from the old system or the
first boot under 12.04.
Getting my system to boot at all under 12.04 was chaotic enough, with
the overly-aggressive /usr/share/initramfs-tools/scripts/mdadm-functions
ravaging my array and then dropping me to a busybox shell over and over
again. I didn't think to record the very first error.
Here's an observation of mine, disks: /dev/sdb1, /dev/sdi1, and
/dev/sdj1 don't have the Raid level "-unknown-", neither are they
labeled as spares. They are in fact, labeled clean and appear
*different* from the others.
Could these disks still contain my metadata from 10.04? I recall during
my installation of 12.04 I had anywhere from 1 to 3 disks unpowered, so
that I could drop in a SATA CD/DVDRW into the slot.
I am downloading 10.04.4 LTS and will be ready to use it soon. I fear
having to do permutations-- 9! (factorial) would mean 362,880
combinations. *gasp*
Many thanks for all your comments and insights.
-EJ
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