Hi, I recently got a new HD and thought it was about time I started using LVM. Unfortunatly, I think I have ended up loosing all of my data due to a typo. I would like to know if my data is lost forever. If not, what can I do now to recover. Here is the whole story... Craig Originally it was set up with 2 HD like this: hda - containing / /home /usr sda - containing one big partition (/dev/sda2) for data storage (SATA drive) I added a new SATA drive and used cfdisk to format it and make one big partition (ext3). My plan was to create a LV on the new HD, copy everything over from the old HD, then add that old HD to the new LV. I followed the LVM HOWTO to create a vg etc: % pvcreate /dev/sdb1 % vgcreate media_vg /dev/sdb1 % lvcreate -L 233G -n media_lv media_vg % mke2fs -j /dev/media_vg/media_lv % mount /dev/media_vg/media_lv /mnt/media ... and everything worked beautifully. I copied everything (188GB) from sda2 onto the new LV successfully. So next was time to prep sda2 to be added to the LV.... this is where I screwed up. % pvcreate /dev/sda2 Physical volume "/dev/sda2" successfully created % vgextend media_vg /dev/sda2 Volume group "media_vg" successfully extended ... I was following some example on a web site, and typed in the wrong device next. The web site had said to use fdisk to change the partition type to 8e. This SHOULD have been sda, but I wrote sdb by mistake: $ fdisk /dev/sdb Command (m for help): t Selected partition 1 Hex code (type L to list codes): 8e Changed system type of partition 1 to 8e (Linux LVM) Command (m for help): p Disk /dev/sdb: 251.0 GB, 251000193024 bytes 255 heads, 63 sectors/track, 30515 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sdb1 1 30515 245111706 8e Linux LVM Command (m for help): w The partition table has been altered! Calling ioctl() to re-read partition table. WARNING: Re-reading the partition table failed with error 16: Device or resource busy. The kernel still uses the old table. The new table will be used at the next reboot. Syncing disks. .... BUT.... I didn't notice the screw up. I wanted to see if the LV would be automaticaly mounted on a reboot without having to add to fstab or an init script (I have been told that this would happen on Debian), so I rebooted. Now neither disc can be seen or mounted. dmesg | tail shows this: % dmesg | tail EXT3-fs error (device sda2): ext3_check_descriptors: Block bitmap for group 0 not in group (block 3258811534)! EXT3-fs: group descriptors corrupted ! EXT3-fs error (device sda2): ext3_check_descriptors: Block bitmap for group 0 not in group (block 3258811534)! EXT3-fs: group descriptors corrupted ! VFS: Can't find ext3 filesystem on dev sdb. ... vgchange can't help out.... % vgchange -a y media_vg Couldn't find device with uuid 'ZHl4Ak-mGS4-wFlF-4neF-G1Ed-GxWB-C4Smj6'. Couldn't find all physical volumes for volume group media_vg. Couldn't find device with uuid 'ZHl4Ak-mGS4-wFlF-4neF-G1Ed-GxWB-C4Smj6'. Couldn't find all physical volumes for volume group media_vg. Unable to find volume group "media_vg" ....vgdisplay can't see either disc (exact same story with lvdisplay)... vgdisplay Couldn't find device with uuid 'ZHl4Ak-mGS4-wFlF-4neF-G1Ed-GxWB-C4Smj6'. Couldn't find all physical volumes for volume group media_vg. Couldn't find device with uuid 'ZHl4Ak-mGS4-wFlF-4neF-G1Ed-GxWB-C4Smj6'. Couldn't find all physical volumes for volume group media_vg. Volume group "media_vg" doesn't exist ... and pvdisplay gives me... % pvdisplay Couldn't find device with uuid 'ZHl4Ak-mGS4-wFlF-4neF-G1Ed-GxWB-C4Smj6'. --- Physical volume --- PV Name /dev/sdb1 VG Name media_vg PV Size 233.75 GB / not usable 0 Allocatable yes PE Size (KByte) 4096 Total PE 59841 Free PE 193 Allocated PE 59648 PV UUID rlnV4y-B4eJ-Pyc0-RLJm-2Zbv-t04C-dxzU1A --- Physical volume --- PV Name unknown device VG Name media_vg PV Size 186.30 GB / not usable 0 Allocatable yes PE Size (KByte) 4096 Total PE 47694 Free PE 47694 Allocated PE 0 PV UUID ZHl4Ak-mGS4-wFlF-4neF-G1Ed-GxWB-C4Smj6 _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/