I was attempting to reallocate unused disk space (1.2Tb) from
/dev/centos/root using the steps in How to move disk space from centos-home to centos-root.
$ umount /dev/mapper/centos-home $ lvreduce -L 1200G /dev/mapper/centos-home
I'm getting a "can't read superblock" error when i try to remount the drive.
$ mount /dev/mapper/centos-home mount: /dev/mapper/centos-home: can't read superblock
Before starting, I double-checked to make sure there w enough free (physical space) before running the 'lvreduce' command (there was 2Tb free) - but assume my error was not running a command to first shrink the file system as suggested in LVM logical volume partition corrupted after lvreduce, but also read that this can't be done on XFS systems pr have been unable to locate the specifics.
I tried to recover using,
$ xfs_repair /dev/mapper/centos-home
but the result said
Sorry, could not find valid secondary superblock; Exiting now.
I also tried to restore the size of the LV
$ lvextend -L 1200G /dev/mapper/centos-home
with the result,
New size (307200 extents) matches existing size (307200 extents)
but got the same
superblock read error when trying to
$ mount the drive.
I'm not sure how deep of a hole I have dug for myself at this point, so here's my question.
What's the best way to recover from this? Or, if I can't recover and mount the damaged drive, do I just delete it and create a new one with the same name? And is this even possible, i.e. do I need to reinstall CentOS? I didn't back up this drive as I haven't been using it. I used the PLESK backup tool so could restore that way, but assume this only works on the
/dev/centos/root drive so wouldn't apply here?
I have 4 physical disks set up as RAID5. The other drives and applications are running fine (PLESK lives on
/dev/centos/root) and I don't want to damage them.
I'd also like to complete the original task of growing
Here's where things are now....
$ pvscan PV /dev/sda3 VG centos lvm2 [2.04 TiB / 838.63 GiB free] Total: 1 [2.04 TiB] / in use: 1 [2.04 TiB] / in no VG: 0 [0 ] $ vgscan Reading volume groups from cache. Found volume group "centos" using metadata type lvm2 $ lvscan ACTIVE '/dev/centos/swap' [4.00 GiB] inherit ACTIVE '/dev/centos/home' [1.17 TiB] inherit ACTIVE '/dev/centos/root' [50.00 GiB] inherit $ pvdisplay --- Physical volume --- PV Name /dev/sda3 VG Name centos PV Size 2.04 TiB / not usable 0 Allocatable yes PE Size 4.00 MiB Total PE 535714 Free PE 214690 Allocated PE 321024 PV UUID qISA9P-0jFe-gk9I-5uuL-OODW-N3af-OkfJlB $ vgdisplay --- Volume group --- VG Name centos System ID Format lvm2 Metadata Areas 1 Metadata Sequence No 6 VG Access read/write VG Status resizable MAX LV 0 Cur LV 3 Open LV 2 Max PV 0 Cur PV 1 Act PV 1 VG Size 2.04 TiB PE Size 4.00 MiB Total PE 535714 Alloc PE / Size 321024 / 1.22 TiB Free PE / Size 214690 / 838.63 GiB VG UUID zzLRUZ-96Vd-5NGr-YsCl-PJ0l-O8Sy-07Dbqu $ lvdisplay --- Logical volume --- LV Path /dev/centos/swap LV Name swap VG Name centos LV UUID Dxqf6A-Jtyp-Qdhx-1C0u-CS40-L95c-qF4tRU LV Write Access read/write LV Creation host, time localhost.localdomain, 2016-12-20 09:00:45 -0500 LV Status available # open 2 LV Size 4.00 GiB Current LE 1024 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:1 --- Logical volume --- LV Path /dev/centos/home LV Name home VG Name centos LV UUID 9QYG2p-0Srl-AluZ-qsBE-wCQ4-BXyN-0hmTp3 LV Write Access read/write LV Creation host, time localhost.localdomain, 2016-12-20 09:00:46 -0500 LV Status available # open 0 LV Size 1.17 TiB Current LE 307200 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:2 --- Logical volume --- LV Path /dev/centos/root LV Name root VG Name centos LV UUID WrqVSs-EkZI-WD7W-AfsL-2PFX-iZLy-8TPjZr LV Write Access read/write LV Creation host, time localhost.localdomain, 2016-12-20 09:01:40 -0500 LV Status available # open 1 LV Size 50.00 GiB Current LE 12800 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:0