Re: RAID 5 inaccessible - continued

[Krekna Mektek <krekna@gmail.com>]

Hi,

Well, the dd_rescue did it's work, the array is now rebuilding, but
it's doing its thing very slowly.

But now the following, while the array is rebuilding and with the good
image on my new disk (The FaultyRAIDDisk.img), I am trying to mount
/dev/md0 already, but it now says :

root@1[~]# fdisk -l /dev/md0

Disk /dev/md0: 800.1 GB, 800171491328 bytes
2 heads, 4 sectors/track, 195354368 cylinders
Units = cylinders of 8 * 512 = 4096 bytes

Disk /dev/md0 doesn't contain a valid partition table

How can some individual disks which crash destroy my partition table!? Help!
Is there some way to get my data back from here??



2006/2/15, David Greaves <david@dgreaves.com>:
> man ddrescue:
>       -r, --max-retries=<n>
>               exit after given retries (-1=infinity) [0]
>
>
> So the -r10 basically tries to re-read each dodgy sector 10 times.
>
> Is it working?
>
> David
>
> Krekna Mektek wrote:
>
> >Hi,
> >
> >I am busy with it now, but what does the 10 mean in -r10 ? I
> >understand from the --help that one can use the -r option, but without
> >something behind it?
> >
> >Krekna
> >
> >2006/2/14, David Greaves <david@dgreaves.com>:
> >
> >
> >>Krekna Mektek wrote:
> >>
> >>
> >>
> >>>I want to rebuilt from the good one and the faulty one. That's why I
> >>>wanted to dd the disk to an image file, but it complains it has no
> >>>boot sector.
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>>>>I did the folowing:
> >>>>>>
> >>>>>>dd conv=noerror if=dev/hdd1 of=/mnt/hdb1/Faulty-RAIDDisk.img
> >>>>>>losetup /dev/loop0 /mnt/hdb1/Faulty-RAIDDisk.img
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>You could try doing this again using ddrescue (google if you need to
> >>install it):
> >>
> >>   ddrescue dev/hdd1 /mnt/hdb1/Faulty-RAIDDisk.img
> >>/mnt/hdb1/Faulty-RAIDDisk.log
> >>
> >>Then do it again using -r10 (to increase the retries on the faulty sectors)
> >>
> >>   ddrescue -r10 dev/hdd1 /mnt/hdb1/Faulty-RAIDDisk.img
> >>/mnt/hdb1/Faulty-RAIDDisk.log
> >>
> >>This will be much quicker because the log file contains details of the
> >>faulty sectors.
> >>With luck (mucho luck) you may not even lose data.
> >>
> >>David
> >>
> >>--
> >>
> >>
> >>
> >>
> >
> >
> >
>
>
> --
>
>