12-29-2010
Lost MBR on disk
trying to recover a lost partition table, where the signature (0x55AA) has been lost, though attempting to restore using a number of tools (fdisk, testdisk et al) the write fails.
also the os is unable to read the disk geometry correctly, after attempting to correct the geometry, the updated geometry fails to save.
im lost as to how to get this rebuilt partition table to save.
9 More Discussions You Might Find Interesting
1. Filesystems, Disks and Memory
First time so excuse my ignorance please.
I may not be accurately describing the issue.
I have inherited a small lab mostly SUN V120s.
We lost power and are trying to recover.
Nope no backups...
The primary issue I have is 1 box is an Oracle Server.
It has 2 36Gb harddrives.
I am able to... (3 Replies)
Discussion started by: murphsr
3 Replies
2. UNIX for Dummies Questions & Answers
I'm confused. Originally I did
telinit 1
cp /dev/sda /dev/sdb
where sda is my boot disk and sdb is a USB disk. This probably copied my MBR.
Since /dev/sdb is 300GB and /dev/sda only 160GB I had a bunch of space left which I decided to experiment with by creating partitions of various... (1 Reply)
Discussion started by: siegfried
1 Replies
3. UNIX for Dummies Questions & Answers
Hi all,
I am newbie here.I want to know what is MBR,boot loader & boot strap programe.
What is procedure of loading OS in to memory.
Thanx in advance:) (1 Reply)
Discussion started by: vishwasrao
1 Replies
4. Ubuntu
Hi All,
Today when I was working on a script to generate custom wordlist. So I ran a script and the output was directed to /tmp.
The disk space was around 19 gb. While the script was running, I decided to direct the o/p file to my 1TB drive. So I broke the run using Ctrl + C.
Now when I... (4 Replies)
Discussion started by: morningSunshine
4 Replies
5. SCO
hi
How can I backup MBR an Partition Table of SCO 5.0.6? (7 Replies)
Discussion started by: ccc
7 Replies
6. Solaris
Hi All
Hope it's okay to post on this sub-forum, couldn't find a better place
I've got a 480R running solaris 8 with veritas volume manager managing all filesystems, including an encapsulated root disk (I believe the root disk is encapsulated as one of the root mirror disks has an entry under... (1 Reply)
Discussion started by: sunnyd76
1 Replies
7. Fedora
Hi,
I just built myself a new machine which has an ASUS motherboard with is UEFI based.
I noticed after I installed Fedora 17 that my sda is MBR and my sdb is GPT:
sda is a ssd drive. Should the ssd drive be GPT or is MBR okay?
sda is 60Gb drive. (3 Replies)
Discussion started by: mojoman
3 Replies
8. Solaris
Hi guys, I appreciate any help in this regard, we have lost sensitive data in the company.
One box with 2 disk mirrored and a 3ware controller handling 13 disks in a raidz2 pool. Suddenly the box restart and keeps "Reading ZFS config" for hours.
Unplugging disk by disk we isolate the disk... (3 Replies)
Discussion started by: tatxo
3 Replies
9. Hardware
Hello everyone. I have a question which I may know the answer to, I'm just looking for a confirmation. When it comes to the MBR of a hard drive, i've read in multiple sources that it's always located in the first sector of the hard drive. Is the MBR there from the factory? When I buy a new blank... (3 Replies)
Discussion started by: Lost in Cyberia
3 Replies
CCD(4) BSD Kernel Interfaces Manual CCD(4)
NAME
ccd -- Concatenated disk driver
SYNOPSIS
pseudo-device ccd [count]
DESCRIPTION
The ccd driver provides the capability of combining one or more disks/partitions into one virtual disk.
This document assumes that you're familiar with how to generate kernels, how to properly configure disks and pseudo-devices in a kernel con-
figuration file, and how to partition disks.
Note that the 'raw' partitions of the disks must not be combined. Each component partition should be offset at least one cylinder from the
beginning of the component disk. This avoids potential conflicts between the component disk's disklabel and the ccd's disklabel. The kernel
will only allow component partitions of type FS_CCD. But for now, it allows partition of all types since some port lacks support of an on-
disk BSD disklabel. The partition of FS_UNUSED may be rejected because device driver of component disk will refuse it.
In order to compile in support for the ccd, you must add a line similar to the following to your kernel configuration file:
pseudo-device ccd 4 # concatenated disk devices
The count argument is how many ccds memory is allocated for at boot time. In this example, no more than 4 ccds may be configured.
A ccd may be either serially concatenated or interleaved. To serially concatenate the partitions, specify the interleave factor of 0.
If a ccd is interleaved correctly, a ``striping'' effect is achieved, which can increase performance. Since the interleave factor is
expressed in units of DEV_BSIZE, one must account for sector sizes other than DEV_BSIZE in order to calculate the correct interleave. The
kernel will not allow an interleave factor less than the size of the largest component sector divided by DEV_BSIZE.
Note that best performance is achieved if all component disks have the same geometry and size. Optimum striping cannot occur with different
disk types.
Also note that the total size of concatenated disk may vary depending on the interleave factor even if the exact same components are concate-
nated. And an old on-disk disklabel may be read after interleave factor change. As a result, the disklabel may contain wrong partition
geometry and will cause an error when doing I/O near the end of concatenated disk.
There is a run-time utility that is used for configuring ccds. See ccdconfig(8) for more information.
WARNINGS
If just one (or more) of the disks in a non-mirrored ccd fails, the entire file system will be lost.
FILES
/dev/{,r}ccd* ccd device special files.
SEE ALSO
config(1), MAKEDEV(8), ccdconfig(8), fsck(8), mount(8), newfs(8)
HISTORY
The concatenated disk driver was originally written at the University of Utah.
BSD
March 5, 2004 BSD