My laptop is unable to boot. So, I run Ubuntu 18.04 live from a bootable USB. It didn't automatically mount the 500 GB hard disk
/dev/sda, which uses GPT.
lsblk shows only the disk, not the partitions;
fdisk is instead able to show them.
gdisk shows the same error as in this page (Section "Semi-Automated Recovery"):
# gdisk /dev/sda GPT fdisk (gdisk) version 0.7.2 Warning! Main partition table CRC mismatch! Loaded backup partition table instead of main partition table!
Then, the linked page shows a list of options for the
recovery/transformation command, in Section "Manual Recovery Procedures", specifying that:
You can experiment with all of the options just described (except for w); none of the data-recovery tools causes immediate writes to the disk.
I didn't understand how can one verify if these options will work or not, before making permanent modifications.
gdisk, is it possible to temporarily use the
backup partition table, so that Ubuntu can mount the
/dev/sda disk partitions, and then leave the disk unchanged when Ubuntu is shut down?