Archive for July 10th, 2010

New 1.5 TB USB Backup Drive

Just got a new 1.5 TB USB drive (Western Digital Elements; every manufacturer has produced horror stores) for $85 delivered; I do not understand the economics of that business in the least. Anyway, this will become the external drive onto which the rsnapshot routine dumps the daily changes from the file server; the old 500 GB drive was 99% full, so it’s time to tuck that one in the fireproof safe.

The NTFS partition had some weird-ass peculiarities that choked cfdisk, so I used parted to blow away the NTFS type=7 partition and create a new Linux type-83 partition. Strangely, the drive came with no shovelware, for which I’m grateful.

sudo fdisk /dev/sde
Command (m for help): d
Selected partition 1
Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-182401, default 1):
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-182401, default 182401):
Using default value 182401
Command (m for help): w
The partition table has been altered!

Then build an ext3 filesystem:

sudo mke2fs -j -m 0 -L 'Backup-1.5TB' -O sparse_super /dev/sde1

The sparse_super option seems to make sense; if the drive fails to the point where you must go rummaging for more than one spare superblock, you’re probably not going to find any of them.

Turns out you really should unplug / replug a USB drive after walloping its partition table. Took me a while to figure that out. Again. You’d think I’d remember.

Then you find the partitions’s new UUID using any of:

ll /dev/disk/by-uuid/
vol_id /dev/sde1

Then plug the UUID into fstab so the rsnapshot routine can mount the drive regardless of which device it wakes up as on any given day:

UUID=77c75554-26a0-4bbc-a452-201c2150bf1a  /mnt/backup ext2 defaults,noatime,noauto,nodev,noexec,nosuid 0 0

More on that from the last go-round there.

The first backup took about six hours to copy 430-some-odd GB of data from the internal SATA drive. Call it almost exactly 20 MB/s; such a nice round number surely means a drive-limited data rate.

Incidentally, if you need a shiny new UUID for some reason, uuidgen is your friend.

Memo to Self: Just unplug the [mumble] drive.

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