Morgan Read wrote:
Hi Folks
This post could equally be titled - is there a God?
Yesterday I ran this command:
[root@morgansmachine DiskBUImagesEtc]# dd if=/dev/sda
of=pocketpc.rescue bs=1M count=33
(No output, just bash history.)
Today I ran these commands:
[root@morgansmachine DiskBUImagesEtc]# dd if=/dev/sda
of=2ndstage.rescue bs=1K count=1280
1280+0 records in
1280+0 records out
1310720 bytes (1.3 MB) copied, 0.0535238 s, 24.5 MB/s
[root@morgansmachine DiskBUImagesEtc]# chown morgan: ./2ndstage.rescue
[root@morgansmachine DiskBUImagesEtc]# dd if=zImage-LAB-20060421.htc
of=/dev/sda
2348+0 records in
2348+0 records out
1202176 bytes (1.2 MB) copied, 0.117155 s, 10.3 MB/s
if you copy that many bytes back from your rescue, and your rescue
didn't get clobbered by the misadventure, you should be about okay, but
you won't really know until you reboot.
A hot backup like that of an active drive is flaky, and a hot restore is
flaky, so we're looking at flaky squared. Dithering around asking for
advice probably gave time for the flakiness to byte.
[root@morgansmachine DiskBUImagesEtc]#
Both yesterday and today I should not have used /dev/sda, but should
have used /dev/sdc... Ouch...
Now I seem to have an unallocated partition of some 37.26GB where once
existed my carefully constructed laptop hard drive.
Everything seems to be running fine, but I expect if I reboot - I
wont! I guess I've just wiped out my MBR or something close.
If you restore the first sector, you will have a good partition table.
You might have filesystem problems, and they may be irrecoverable, you
won't know until you try it. You can assess it by running fdisk against
your backup file, a bit like this:
Disk /dev/hda: 40.0 GB, 40016019456 bytes
255 heads, 63 sectors/track, 4865 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/hda1 * 1 13 104391 83 Linux
/dev/hda2 14 4865 38973690 8e Linux LVM
09:46 [summer@numbat ~]$
On this drive I have 14 blocks before the start of the first partition.
If you haven't clobbered the first partition, you will be in good shape
of you resore the MBR, the first sector. The drive might not boot, but
that's fixable by reinstalling grub.
If your first effort fails and you're about ready to reinstall and write
off the disk, use Knoppix for your further recovery efforts, it has a
more complete toolset than Fedora rescue CDs.
I don't know about Fedora Live media.
So, fingers firmly crossed, have I managed to copy enough of my hard
drive with the first two commands to be able to patch back the
catastrophic damage I seem to have done with the last command. Could
someone more confident than I give me some instruction:)
Any help desperately welcome.
Regards,
Morgan.
