Repair GPT Table
From WikiMLT
Gere is presented a list of the steps that I've applied to repair the GPT table of one of my devices.
Create a Backup of the Partition Table
First things first – create a backup copy of the partition table.
sudo sfdisk -d /dev/sda > /mnt/backups/gpt_table_sda_cx250.txt
Repair the GPT Partition Table
Here I'm using the gdisk tool but for similar tasks there is a plenty of other tolls is available. As final result the partition table is repaired and also a backup copy is written to the disk. In the listing below are used the following gdisk's commands:
pprint the partition table,vverify disk,wwrite table to disk and exit.
sudo gdisk /dev/sda
GPT fdisk (gdisk) version 1.0.5
Partition table scan:
MBR: protective
BSD: not present
APM: not present
GPT: present
Found valid GPT with protective MBR; using GPT.
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): p
Disk /dev/sda: 488397168 sectors, 232.9 GiB
Model: CT250MX500SSD1
Sector size (logical/physical): 512/4096 bytes
Disk identifier (GUID): 0AC2B894-BAE7-4790-80F9-1934C8F84E24
Partition table holds up to 128 entries
Main partition table begins at sector 2 and ends at sector 33
First usable sector is 34, last usable sector is 488397134
Partitions will be aligned on 2048-sector boundaries
Total free space is 4397 sectors (2.1 MiB)
Number Start (sector) End (sector) Size Code Name
1 2048 1050623 512.0 MiB EF00
2 1050624 488394751 232.4 GiB 8300
Command (? for help): v
No problems found. 4397 free sectors (2.1 MiB) available in 2
segments, the largest of which is 2383 (1.2 MiB) in size.
Command (? for help): w
Final checks complete. About to write GPT data. THIS WILL OVERWRITE EXISTING
PARTITIONS!!
Do you want to proceed? (Y/N): y
OK; writing new GUID partition table (GPT) to /dev/sda.
Warning: The kernel is still using the old partition table.
The new table will be used at the next reboot or after you
run partprobe(8) or kpartx(8)
The operation has completed successfully.
References
