I will access the volume as root as you suggested. As for the second
disk, it was RAID 5, and your response was pretty much what I
suspected. Oh, well.
Thank you for your response.
Jim
On Dec 1, 2005, at 8:59 AM, Nicholas Leippe wrote:
On Thursday 01 December 2005 04:12 am, James Clawson wrote:
Greetings to my fellow Linux users,
I need to mount two HDDs for data recovery purposes. One is a disk
which contains three valid Linux partitions, and the other was once
part of a RAID which spanned three disks.
The first HDD is in a computer which will boot, but for which I have
no username or password lists. I can mount the partitions on that
disk while running Linux from a different HDD and, as root, change
the ownership and permissions of all of the files on that HDD, which
would allow me to recover the data I need from the drive. The result
of this would be that that drive would no longer be a usable Linux
install. As that result is not desirable, I intend to duplicate all
of those partitions using dd and then extract the data from the
duplicate volume. Does anyone know of a better solution to this?
You shouldn't need to change the ownership and permissions to
access the files
as root. You can just mount it ro and get anything off from it
that you need
without affecting the installation. (Or just edit /etc/passwd and
boot it.)
I have retrieved a fair amount of data already from the second HDD by
use of foremost. Thank you to those on the list who recommended that
application to me earlier this year. Unfortunately, I have
encountered a problem using that tool, as the drive was fragmented,
and any file larger than a few blocks seems to be broken up due to
that fragmentation. However, I believe I have repaired the surface
of the volume sufficiently such that where I able to reassemble the
RAID, I believe the disk, would be usable. As the other two disks of
the RAID are not usable, that is not an option. Is there any way to
access the raw files on that disk without the remainder of the RAID?
Is there any way to rebuild or reorder the segments to minimize the
impact of fragmentation on the volume?
Depends on the raid level.
raid 0, you're out of luck. You've only got 1/3rd of the data you
need.
raid 1, you're in luck, you can just treat the drive as a single
volume and
continue your data recovery attempts.
raid 5, you're out of luck, You've only got 1/2 of the data you need.
If it was raid 0 or raid 5, the 'fragmentation' you're seeing is
from the
blocks of the files (in 'chunk' sizes specified when the md
partition is
created) are distributed between the drives in the array--IOW not
all of the
data was ever even on the drive.
Additionally, if this is the case, any 'repairing' that includes
moving blocks
around would make reassembling the array impossible as their
location is
predefined by the array--the array would now be scrambled.
--
Respectfully,
Nicholas Leippe
Sales Team Automation, LLC
1335 West 1650 North, Suite C
Springville, UT 84663 +1 801.853.4090
http://www.salesteamautomation.com
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