Hello all
I have two sets of eIDE hard drives from earlier servers, one centos & one fedora. Both were LVM volumes with three or four physical disks, with ext3 fs. One disk, maybe even the boot one may even be missing, either from one or both sets and we do not know the disk order. I got these left from an earlier sysadmin who left the company & nobody know what's what.
I need to recover data so I need to backup each of the disks to a disk image file first, then find block-size/recover lvm metadata on the volume, mount the volume to my current server and recover whatever files can be recovered manually.
My question is:
- what switches to be used with dd in creating the image, so that I retain the lvm disk data, for future recovery, if I mess up the recovery job? Can you please give the actual command assuming disk is connected at /dev/sdb?
- How do I find the blocksize used by the disk & how do I get the meta-data and mount the disk to current lvm fs.
Request please give me step by step process. I am finding the howtos & examples on the net very daunting as most of them have co-issues of raid etc. Mine is a plain lvm spanning multiple disks.
I don't have expertise of this level & suddenly my boss is expecting me to perform a miracle.
Please help.
With best regards. Sanjay.
On Thu, 2011-02-03 at 16:28 +0530, Sanjay Arora wrote:
Hello all
I have two sets of eIDE hard drives from earlier servers, one centos & one fedora. Both were LVM volumes with three or four physical disks, with ext3 fs. One disk, maybe even the boot one may even be missing, either from one or both sets and we do not know the disk order. I got these left from an earlier sysadmin who left the company & nobody know what's what.
I need to recover data so I need to backup each of the disks to a disk image file first, then find block-size/recover lvm metadata on the volume, mount the volume to my current server and recover whatever files can be recovered manually.
My question is:
- what switches to be used with dd in creating the image, so that I
retain the lvm disk data, for future recovery, if I mess up the recovery job? Can you please give the actual command assuming disk is connected at /dev/sdb?
- How do I find the blocksize used by the disk & how do I get the
meta-data and mount the disk to current lvm fs.
Request please give me step by step process. I am finding the howtos & examples on the net very daunting as most of them have co-issues of raid etc. Mine is a plain lvm spanning multiple disks.
I don't have expertise of this level & suddenly my boss is expecting me to perform a miracle.
man scanvg
On Thu, 2011-02-03 at 16:28 +0530, Sanjay Arora wrote:
Hello all
I have two sets of eIDE hard drives from earlier servers, one centos & one fedora. Both were LVM volumes with three or four physical disks, with ext3 fs. One disk, maybe even the boot one may even be missing, either from one or both sets and we do not know the disk order. I got these left from an earlier sysadmin who left the company & nobody know what's what.
I need to recover data so I need to backup each of the disks to a disk image file first, then find block-size/recover lvm metadata on the volume, mount the volume to my current server and recover whatever files can be recovered manually.
My question is:
- what switches to be used with dd in creating the image, so that I
retain the lvm disk data, for future recovery, if I mess up the recovery job? Can you please give the actual command assuming disk is connected at /dev/sdb?
- How do I find the blocksize used by the disk & how do I get the
meta-data and mount the disk to current lvm fs.
Request please give me step by step process. I am finding the howtos & examples on the net very daunting as most of them have co-issues of raid etc. Mine is a plain lvm spanning multiple disks.
I don't have expertise of this level & suddenly my boss is expecting me to perform a miracle.
man scanvg
-----------------------
I think Terry meant 'man vgscan', but I have not connected the dots to be able to mount an lvm volume from a different machine either.
Greg
On Fri, Feb 4, 2011 at 6:23 AM, Gregory P.. Ennis PoMec@pomec.net wrote:
I think Terry meant 'man vgscan', but I have not connected the dots to be able to mount an lvm volume from a different machine either.
Greg
Actually I think there should be some LVM uuid magic....but maybe I'll learn more from errors when I try to mount or whatever....since I have not run vgscan, don't know....getting a big hdd for dd images...will start trial & error after.
Sanjay.
also, if the disk is multi-disk, which is the case here, you can look into /etc/lvm/backup for LVM meta data information.
----- Original Message ----- | Hello all | | I have two sets of eIDE hard drives from earlier servers, one centos & | one fedora. Both were LVM volumes with three or four physical disks, | with ext3 fs. One disk, maybe even the boot one may even be missing, | either from one or both sets and we do not know the disk order. I got | these left from an earlier sysadmin who left the company & nobody know | what's what. | | I need to recover data so I need to backup each of the disks to a disk | image file first, then find block-size/recover lvm metadata on the | volume, mount the volume to my current server and recover whatever | files can be recovered manually. | | My question is: | | - what switches to be used with dd in creating the image, so that I | retain the lvm disk data, for future recovery, if I mess up the | recovery job? Can you please give the actual command assuming disk is | connected at /dev/sdb? | | - How do I find the blocksize used by the disk & how do I get the | meta-data and mount the disk to current lvm fs. | | Request please give me step by step process. I am finding the howtos & | examples on the net very daunting as most of them have co-issues of | raid etc. Mine is a plain lvm spanning multiple disks. | | I don't have expertise of this level & suddenly my boss is expecting | me to perform a miracle. | | Please help. | | With best regards. | Sanjay. | _______________________________________________ | CentOS mailing list | CentOS@centos.org | http://lists.centos.org/mailman/listinfo/centos
Thanks guys...will try these!
On Fri, Feb 4, 2011 at 1:08 AM, James A. Peltier jpeltier@sfu.ca wrote:
also, if the disk is multi-disk, which is the case here, you can look into /etc/lvm/backup for LVM meta data information.
----- Original Message ----- | Hello all | | I have two sets of eIDE hard drives from earlier servers, one centos & | one fedora. Both were LVM volumes with three or four physical disks, | with ext3 fs. One disk, maybe even the boot one may even be missing, | either from one or both sets and we do not know the disk order. I got | these left from an earlier sysadmin who left the company & nobody know | what's what. | | I need to recover data so I need to backup each of the disks to a disk | image file first, then find block-size/recover lvm metadata on the | volume, mount the volume to my current server and recover whatever | files can be recovered manually. | | My question is: | | - what switches to be used with dd in creating the image, so that I | retain the lvm disk data, for future recovery, if I mess up the | recovery job? Can you please give the actual command assuming disk is | connected at /dev/sdb? | | - How do I find the blocksize used by the disk & how do I get the | meta-data and mount the disk to current lvm fs. | | Request please give me step by step process. I am finding the howtos & | examples on the net very daunting as most of them have co-issues of | raid etc. Mine is a plain lvm spanning multiple disks. | | I don't have expertise of this level & suddenly my boss is expecting | me to perform a miracle. | | Please help. | | With best regards. | Sanjay. | _______________________________________________ | CentOS mailing list | CentOS@centos.org | http://lists.centos.org/mailman/listinfo/centos
-- James A. Peltier IT Services - Research Computing Group Simon Fraser University - Burnaby Campus Phone : 778-782-6573 Fax : 778-782-3045 E-Mail : jpeltier@sfu.ca Website : http://www.sfu.ca/itservices http://blogs.sfu.ca/people/jpeltier
CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
-
Gregory P.. Ennis -
James A. Peltier -
Sanjay Arora -
Terry Polzin