Seemed to work on the first boot:
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# fdisk -l
Disk /dev/sdb: 4000.8 GB, 4000787030016 bytes
255 heads, 63 sectors/track, 486401 cylinders, total 7814037168 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
Disk identifier: 0xf37693aa
Device Boot Start End Blocks Id System
/dev/sdb1 256 73215 36480 b W95 FAT32
/dev/sdb2 73216 3519069871 1759498328 83 Linux
At first this may seem correct; the small FAT32 partition could be tools leftovers from vendor (backup, etc), and the large partition could be my ext4 data partion. However, after deciphering the block numbers I see that the size of sdb2 is just 1800MB, leaving 2200MB of unused space.
I know for a fact that my ext4 partition on this drive was 4TB! (it is also likely that I deleted any existing partitions before creating the ext4, i.e the small FAT partition shouldn't be there - but I cannot remember this for sure)
I'm not sure if my data-partition being number 2 is correct, but I have no way of verifying that as my fstab entry for the partition when the drive was hooked up via the usb enclosure used the uuid:
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UUID=e23482c0-5c2b-48ac-9884-b9c9073959e6 /media/4tb ext4 defaults 0 0
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# mount -t ext4 /dev/sdb2 /media/4tb/
mount: wrong fs type, bad option, bad superblock on /dev/sdb2,
missing codepage or helper program, or other error
In some cases useful info is found in syslog - try
dmesg | tail or so
After a lot og googling, testing, failing and googling again I ended up installing the 'testdisk' tool.
Testdrive finds same incorrect partition table
testdisk found my drive, I selected "Intel" partition layout (sounded logical to me), and I ran "Analyze" which gave results similar to "fdisk -l", a small FAT partition and a Linux partition taking up almost 50% of the drive:
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Disk /dev/sdb - 4000 GB / 3726 GiB - CHS 486401 255 63
Current partition structure:
Partition Start End Size in sectors
Invalid FAT boot sector
1 P FAT32 0 4 5 4 142 10 72960
1 P FAT32 0 4 5 4 142 10 72960
Bad relative sector.
No ext2, JFS, Reiser, cramfs or XFS marker
2 P Linux 4 142 11 219051 246 59 3518996656
2 P Linux 4 142 11 219051 246 59 3518996656
Bad relative sector.
No partition is bootable
Testdrive with partition layout "None" is more promising
I run analyze again:
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Disk /dev/sdb - 4000 GB / 3726 GiB - CHS 486401 255 63
Partition Start End Size in sectors
>P ext4 36 117 18 486401 80 63 7813451440
Structure: Ok.
Keys T: change type, P: list files,
Enter: to continue
EXT4 Large file Sparse superblock, 4000 GB / 3725 GiB
Anyway, I try to hit "P" (to list files, as suggested), but get this error:
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Can't open filesystem. Filesystem seems damaged.
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Write isn't available because the partition table type "None" has been selected.
Questions
* What does Intel/None partition layout mean?
"Intel" layout = 1 tiny fat partition + 1 Linux (note - didn't say ext4) partition ~50% of the drive
"None" layout = 1 ext4 partition - 4TB (I want this one)
* Why is my seemingly correct partition table only found using the "None" layout?
Could it be the usb/sata adapter in the LaCie enclosure uses "None" -layout on the SATA side, but "Intel" on the USB side, thus making it difficult to re-use the disk outside the enclosure without a complete reformat?
The problem could of course be caused by a bricked disk too, I know that, but no bad sector symptoms so far.
All of the linux tools (fdisk, parted, cfdisk) seem to default to the Intel layout, so if it's possible I want to restore the partition table found using layout "None", as it seems to be correct. Can it be done? I'm not afraid of losing the data, but would be happy to have them back.
Disclaimer: I have never ever before heard about different partition layouts (intel, none...), so please bear with me if the questions seem stupid.
Anyone?
Thanks!!
/Geir