This is weird...

sudo parted /dev/sdb mklabel gpt
sudo parted /dev/sdb print

Disk /dev/sdb: 6978GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt

Number Start End Size File system Name Flags
1 17.4kB 6978GB 6978GB ext3 primary

sudo parted /dev/sdb mkpart primary 0 6978GB

sudo mkfs.ext3 /dev/sdb1

cat /proc/partitions
8 0 20971519 sda
8 1 248976 sda1
8 2 1951897 sda2
8 3 18763920 sda3
8 16 6814820352 sdb
8 17 6814820319 sdb1

sudo fsck /dev/sdb1
fsck 1.40-WIP (14-Nov-2006)
e2fsck 1.40-WIP (14-Nov-2006)
/dev/sdb1: clean, 11/851853312 files, 26779760/1703705079 blocks

sudo vol_id /dev/sdb1

>/etc/fstab : UUID=blah /test ext3 defaults 0 0

reboot.

sudo fsck /dev/sdb1
fsck 1.40-WIP (14-Nov-2006)
e2fsck 1.40-WIP (14-Nov-2006)
The filesystem size (according to the superblock) is 1703705079 blocks
The physical size of the device is 93092343 blocks
Either the superblock or the partition table is likely to be corrupt!
Abort<y>? yes

cat /proc/partitions
major minor #blocks name

8 0 20971519 sda
8 1 248976 sda1
8 2 1951897 sda2
8 3 18763920 sda3
8 16 6814820352 sdb
8 17 372369375 sdb1


What has changed? I dont get it. I just reboot, and everything goes to hell.

Just FYI, GPT is enabled in the kernel...

The thing is... if I run mkfs.ext3 on /dev/sdb (create the whole thing as a partition) then there is no problem. Everything seems to work perfectly.

BUT, I am worried this is in some way a "bad thing".

And me losing 6 Tb of data might be a "bad thing" for me too. Ahem.

was this big partition initially attempted to be created with fdisk (especially during an OS install?) If so, you may want to use fdisk to delete the partition, write to the partition table, then use parted. The error message you're getting looks like one that comes from fdisk trying to make a partition larger than 2TB.

I don't think it matters, but you know that parted has its own "shell". You can just run "sudo parted" and then run commands from there. Otherwise, the commands you're giving look correct.

FWIW - For some reason, I always give a little bit of a buffer when making my really large partitions - never exactly the entire disk, but a few gigs short.