I partitioned and formatted a 2TB HDD connected with an USB HDD adapter to a Debian system running under VMware, copied the files and moved the HDD to an old P4 system with Debian and a non-AHCI capable BIOS. The HDD showed up as a 232.9GB one:
1 2 | Device Boot Start End Sectors Size Id Type /dev/sdc1 256 488378645 488378390 232.9G 83 Linux |
After googling a while I found out that the problem is with the BIOS reporting the HDD to the OS as if it had 512 bytes long sectors, not 4096 ones.
I could mount the ext4 file system with losetup by telling that it starts at byte no. 8*256 = 2048:
1 2 | losetup /dev/loop0 /dev/sdc -o 2048 mount /dev/sdc1 /home/storage4 |
A permanent fix is to edit the HDD’s MBR partition table to have the file system start at the correct byte no. I exported the partition table to a text file with sfdisk:
1 | sfdisk -d /dev/sdc > sdc.partitions.sfdisk.text |
Then opened the file and edited the start value to 2048, and size to 8*488378390=3907027120. After that I wrote back the partition table to the drive:
1 | cat sdc.partitions.sfdisk.text | sfdisk /dev/sdc |
After running partprobe everything was all right again.
1 2 3 4 5 6 7 8 9 | Disk /dev/sdc: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disklabel type: dos Disk identifier: 0x0006aac3 Device Boot Start End Sectors Size Id Type /dev/sdc1 2048 3907029167 3907027120 1.8T 83 Linux |
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