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<div class="moz-cite-prefix">HI Fay,<br>
<br>
Glad to help. So you have now identified two disks with the
partition scheme that<br>
you show below - good news. The fdisk output shows an "id" column
(which is what<br>
I meant by "type"). Most of your partitions are id=fd (0xfd), and
these are the<br>
mdraid partitions. The swap partition has "82" for its "id".
Normal linux partitions<br>
show "83" here. I doubt your previous attempt to mount the
filesystems via the<br>
usual /dev/sdxx devices would have caused harm, perhaps just a "no
filesystem found"<br>
error or similar.<br>
<br>
I've never done a RAID install of Debian - in fact it looks
complicated from what I've<br>
googled - how did you do that ? (openSUSE is easier in this
respect)<br>
<br>
Anyway, you seem to have SIX raid partitions (1, 5, 6, 7, 8, 10)
on this disk. I'd guess<br>
these are for:<br>
<br>
=======================================================<br>
Device Boot Start End
Blocks Id System
<b>My guess</b><br>
/dev/sdc1 2048 976895 487424
fd Linux raid autodetect
<b>/boot</b><br>
/dev/sdc2 978942 976771071 487896065 5
Extended
<br>
/dev/sdc5 978944 20508671 9764864 fd
Linux raid autodetect
<b>/</b><br>
/dev/sdc6 20510720 59570175 19529728 fd Linux
raid autodetect
<b>/usr</b><br>
/dev/sdc7 59572224 157227007 48827392 fd Linux
raid autodetect
<b>/var</b><br>
/dev/sdc8 157229056 166991871 4881408 fd Linux
raid autodetect
<b>/tmp</b><br>
/dev/sdc9 166993920 176756735 4881408 82 Linux
swap / Solaris
<br>
/dev/sdc10 176758784 976771071 400006144 fd Linux
raid autodetect
<b>/home</b><br>
=======================================================<br>
<br>
I'd boot a live CD again, with ONE of these raid drives in the
caddy and do this to<br>
read-only mount /home so you can take a backup of it:<br>
<br>
1) detect / assemble the raid volumes<br>
<br>
mdadm --assemble --scan<br>
<br>
2) verify this worked, study output and study /proc/mdstat<br>
<br>
cat /proc/mdstat<br>
<br>
3) determine which meta device was just created for each raid
volume - the above<br>
command show this, but also do:<br>
<br>
ls -l /dev/md<br>
<br>
You should see devices under there.<br>
<br>
This may also be useful:<br>
<br>
cat /proc/partitions<br>
dmesg<br>
<br>
4) I found your mdadm output confusing - I'd normally expect to
only see one set<br>
of output from it, yours contains two. The first showed this:<br>
<br>
mdadm: /dev/md/jill:5 has been started with 1 drive (out of 2).
<br>
mdadm: /dev/md/jill:4 has been started with 1 drive (out of 2).
<br>
mdadm: /dev/md/jill:3 has been started with 1 drive (out of 2).
<br>
mdadm: /dev/md/jill:2 has been started with 1 drive (out of 2).
<br>
mdadm: /dev/md/jill:1 has been started with 1 drive (out of 2).
<br>
mdadm: /dev/md/jill:0 has been started with 1 drive (out of 2).
<br>
<br>
5) In the above it looks like /dev/md/jii:5 is associated with
raid volume on sdc10, this<br>
should be your /home partition.<br>
<br>
On openSUSE, which is where I've done all my soft raid, devices
are typically /dev/md0<br>
and /dev/md1... Sometimes I've seen /dev/md127 and /dev/md127.
Your names look<br>
different - if anybody knows how those names are allocated I'd be
interested to here it.<br>
<br>
Assuming /dev/md/jill:5 is the one you can mount it read-only
using:<br>
<br>
mount -o ro /dev/md/jill:5 /mnt/somewhere<br>
<br>
NOTE: read-only == damage limitation - don't be tempted to omit
"-o ro"<br>
<br>
If /mnt/somewhere contains your user profile then copy it to some
other media<br>
using cp/rsync or similar.<br>
<br>
If /mnt/somewhere looks like /, /usr, /var, /boot or /tmp then
umount it and try another.<br>
<br>
Repeat for any other partitions you want to backup. Perhaps you
had a /www<br>
or other partition and my guess above isn't 100% ?<br>
<br>
If you had another motherboard you may be able to resurrect this
system and boot<br>
it but I'd backup data first. (boot rescue, mount raid, chroot,
mkinitrd)<br>
<br>
Hope that helps.<br>
<br>
Regards.<br>
<br>
--<br>
Dave Garry<br>
<br>
On 30/12/13 08:18, Fay Zee wrote:<br>
</div>
<blockquote
cite="mid:20131230081845.19326wtfrh0dpzdx@www.eglug.org.uk"
type="cite">Quoting Dave Garry <a class="moz-txt-link-rfc2396E" href="mailto:daveg@firsdown.dyndns.org"><daveg@firsdown.dyndns.org></a>
on Sun, 29 Dec 2013 11:46:14:
<br>
Thanks a lot, Dave, I'm grateful for your help.
<br>
<br>
<blockquote type="cite">Hi Fay,
<br>
<br>
If the disks were using Linux soft RAID (mdadm) then this site
should be helpful:
<br>
</blockquote>
<br>
Thanks for the link, I read through most of the sections.
<br>
<br>
<blockquote type="cite"><a class="moz-txt-link-freetext" href="https://raid.wiki.kernel.org/index.php/Linux_Raid">https://raid.wiki.kernel.org/index.php/Linux_Raid</a>
<br>
<br>
First you need to identify which of two of the three disks were
being used as the
<br>
RAID mirrors. Booting a live disk with one disk in a caddy is
the way to start.
<br>
<br>
The output from "fdisk -l" should be all you need to identify
the disks - look at the
<br>
"partition type" field - those that are "0xfd" are software
RAID.
<br>
</blockquote>
<br>
fdisk -l was a great help and showed me which two were the
mirrors.
<br>
I didn't see a "partition type" field and there was no mention of
"0xfd".
<br>
<br>
This is my output from fdisk -l. It was identical for both disks:
<br>
<br>
Disk /dev/sdc: 500.1 GB, 500107862016 bytes
<br>
255 heads, 63 sectors/track, 60801 cylinders, total 976773168
sectors
<br>
Units = sectors of 1 * 512 = 512 bytes
<br>
Sector size (logical/physical): 512 bytes / 512 bytes
<br>
I/O size (minimum/optimal): 512 bytes / 512 bytes
<br>
Disk identifier: 0x000cd29d
<br>
<br>
Device Boot Start End Blocks Id System
<br>
/dev/sdc1 2048 976895 487424 fd Linux raid
autodetect
<br>
/dev/sdc2 978942 976771071 487896065 5 Extended
<br>
/dev/sdc5 978944 20508671 9764864 fd Linux raid
autodetect
<br>
/dev/sdc6 20510720 59570175 19529728 fd Linux raid
autodetect
<br>
/dev/sdc7 59572224 157227007 48827392 fd Linux raid
autodetect
<br>
/dev/sdc8 157229056 166991871 4881408 fd Linux raid
autodetect
<br>
/dev/sdc9 166993920 176756735 4881408 82 Linux swap
/ Solaris
<br>
/dev/sdc10 176758784 976771071 400006144 fd Linux raid
autodetect
<br>
<br>
<blockquote type="cite">Commands such as "mdadm --assemble --scan"
will probe the disk for RAID
<br>
volumes, these will then be accessible via /dev/mdxx where xx
will be unique for
<br>
each volume.
<br>
</blockquote>
<br>
"mdadm --assemble --scan" worked for me and I saw the unique
reference, but am still not sure what to type to get access.
<br>
<br>
These are the two outputs from mdadm --assemble --scan:
<br>
<br>
mdadm: /dev/md/jill:5 has been started with 1 drive (out of 2).
<br>
mdadm: /dev/md/jill:4 has been started with 1 drive (out of 2).
<br>
mdadm: /dev/md/jill:3 has been started with 1 drive (out of 2).
<br>
mdadm: /dev/md/jill:2 has been started with 1 drive (out of 2).
<br>
mdadm: /dev/md/jill:1 has been started with 1 drive (out of 2).
<br>
mdadm: /dev/md/jill:0 has been started with 1 drive (out of 2).
<br>
<br>
mdadm: /dev/md/jill:5_0 has been started with 1 drive (out of 2).
<br>
mdadm: /dev/md/jill:4_0 has been started with 1 drive (out of 2).
<br>
mdadm: /dev/md/jill:3_0 has been started with 1 drive (out of 2).
<br>
mdadm: /dev/md/jill:2_0 has been started with 1 drive (out of 2).
<br>
mdadm: /dev/md/jill:1_0 has been started with 1 drive (out of 2).
<br>
mdadm: /dev/md/jill:0_0 has been started with 1 drive (out of 2).
<br>
<br>
What should my mount command be to access each disk?
<br>
<br>
<br>
<blockquote type="cite">You cannot / should not mount the volume
via /dev/sdxx, always
<br>
use the /dev/mdxx device as found by mdadm.
<br>
</blockquote>
<br>
Might I have damaged the data by trying to mount the disks by that
method last week?
<br>
<br>
<blockquote type="cite">The command "cat /proc/mdstat" will show
stats on each RAID volume.
<br>
<br>
When only using one disk from a mirrored pair the volumes will
be in degraded
<br>
mode - "cat /proc/mdstat" will show this. You should be able to
mount the volumes
<br>
read-only to get to your data...
<br>
<br>
If hardware RAID was being used then the above may not be of
use, and you
<br>
may need another motherboard with the same RAID chipset to be
able to read
<br>
them.
<br>
<br>
I hope this helps.
<br>
<br>
Regards.
<br>
<br>
--
<br>
Dave Garry
<br>
</blockquote>
<br>
<blockquote type="cite">
<br>
On 29/12/13 04:53, Fay Zee wrote:
<br>
<blockquote type="cite">Hi, Can anyone advise me how to retrieve
data from a mirrored disk, please?
<br>
<br>
I tried putting each disk into an external HDD caddy on two
other Linux machines but could not read them, and did not get
any meaningful information when running a live gparted disk.
<br>
<br>
The mirrored disks are 500GB SATA but there is also an
additional 500GB SATA disk in the machine, which I wasn't
using. I don't know which two are the mirrors.
<br>
<br>
My (desktop) motherboard has developed a fault. The machine
boots up and the disks spin, and there are beeps which we've
compared to the manual, but I am not getting graphics. There
are no graphics with a live CD or DVD either.
<br>
<br>
Ten minutes and two start-ups prior to this fault, the boot up
message reported that it started up with only one of the
mirrored disks.
<br>
<br>
The operating system is Debian Squeeze, installed in mirror
mode.
<br>
<br>
The motherboard actually supports mirroring but I believe the
mirroring is entirely software driven.
<br>
<br>
I had intended to upgrade to Debian Wheezy at the beginning of
December, so skipped a back-up.
<br>
<br>
I had a friend round who repairs hardware for a living. We
tried removing the battery, shorting out the bios, swapping
out the monitor, the graphics card, the power unit and took
out the memory sticks in turn, as well as testing all the
connections.
<br>
<br>
It is a Gigabyte GA M720 US3 nVidia chipset dual bios with
extra thick copper.
<br>
The processor is AMD Phenom II AM2+ quad core 940.
<br>
The graphics card is 512MB DDR3 nVidia Geforce 9600GT PCI
express - there is no onboard graphics.
<br>
There are four 2GB dual channel DDR2 800 PC2 6400 RAM memory
sticks.
<br>
<br>
The machine was built for me in 2009.
<br>
<br>
<br>
Best regards,
<br>
Fay
<br>
-- <br>
East Grinstead Linux User Group
<br>
<a class="moz-txt-link-abbreviated" href="http://www.eglug.org.uk">www.eglug.org.uk</a>
<br>
<br>
<br>
</blockquote>
<br>
<br>
-- <br>
Sussex mailing list
<br>
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<br>
E-mail Address: <a class="moz-txt-link-abbreviated" href="mailto:sussex@mailman.lug.org.uk">sussex@mailman.lug.org.uk</a>
<br>
Sussex LUG Website: <a class="moz-txt-link-freetext" href="http://www.sussex.lug.org.uk/">http://www.sussex.lug.org.uk/</a>
<br>
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<br>
<br>
</blockquote>
<br>
<br>
<br>
Best regards,
<br>
Fay
<br>
--
<br>
East Grinstead Linux User Group
<br>
<a class="moz-txt-link-abbreviated" href="http://www.eglug.org.uk">www.eglug.org.uk</a>
<br>
<br>
<br>
</blockquote>
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