Repair corrupt GPT partition on graid mini disk
I'm trying to repair a GPT corrupt partition table on a graid mini 1TB external hard drive. Here is the report from gdisk:
root@philippe-desktop:/home/philippe/thomasdisk# gdisk /dev/sdb
GPT fdisk (gdisk) version 0.8.8
Caution: invalid main GPT header, but valid backup; regenerating main header
from backup!
Partition table scan:
MBR: protective
BSD: not present
APM: not present
GPT: damaged
****************************************************************************
Caution: Found protective or hybrid MBR and corrupt GPT. Using GPT, but disk
verification and recovery are STRONGLY recommended.
****************************************************************************
Command (? for help): ?
b back up GPT data to a file
c change a partition's name
d delete a partition
i show detailed information on a partition
l list known partition types
n add a new partition
o create a new empty GUID partition table (GPT)
p print the partition table
q quit without saving changes
r recovery and transformation options (experts only)
s sort partitions
t change a partition's type code
v verify disk
w write table to disk and exit
x extra functionality (experts only)
? print this menu
Command (? for help): v
No problems found. 262157 free sectors (128.0 MiB) available in 2
segments, the largest of which is 262151 (128.0 MiB) in size.
Command (? for help): p
Disk /dev/sdb: 1953546304 sectors, 931.5 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): FE2326A4-F411-489E-B0D9-D2D9EF21A00C
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 1953546270
Partitions will be aligned on 8-sector boundaries
Total free space is 262157 sectors (128.0 MiB)
Number Start (sector) End (sector) Size Code Name
1 40 409639 200.0 MiB EF00 EFI System Partition
2 409640 1953284119 931.2 GiB AF00 G-RAID mini
Command (? for help):
It is my understanding that gdisk is automagically able to work around the corruption and that simply pressing w
should repair my disk, but I'm unsure as usually the v
(verify) option should propose revovery options to me.
Can I safely go and press w
? I already did sgdisk -b backup.gpt /dev/sdb
p.s: please redirect me to the correct website if this question is offtopic
If you spend a few minutes reading your output above you'll find gdisk
is telling you what to do (it found a problem: invalid main GPT header, but valid backup;
, and took an action for you: regenerating main header from backup!
. It's also making a recommendation: disk verification and recovery are STRONGLY recommended.
-- you should probably follow the recommendation).
Based on the fact that verification didn't return any problems you're probably OK writing out the partition layout - my understanding is gdisk
will use & write out the regenerated GPT data.
If you want to be explicit in your actions the recovery menu has an option to use the backup GPT header (rebuilding/replacing the main GPT header) which you can specifically invoke, and that would appear to be the correct action to take (provided the GPT layout you're seeing above looks sane - otherwise you might have to manually rebuild your partition layout).