One Terabyte

Spinning those external USB hard disks

1TB Caviar should be 1024 gigabytes.


hendry@i7 ~$ sudo fdisk -l /dev/sdb

Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0xdd67f844

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1      121601   976760001   83  Linux

hendry@i7 ~$ cat /proc/partitions | grep sdb
   8       16  976762584 sdb
   8       17  976760001 sdb1


/dev/sdb1 on /mnt/home type xfs (rw)
/dev/sdb1             932G  4.2M  932G   1% /mnt/home

Totally gut feeling iotop -b with a sudo rsync -art /home/ /mnt/home/

Total DISK READ: 54.97 M/s | Total DISK WRITE: 56.83 M/s

Seemed like it was quite a good rate from the /dev/sda4 on /home type ext4 (rw).


/dev/sdb1 on /mnt/home type reiserfs (rw)
/dev/sdb1             932G   33M  932G   1% /mnt/home

hendry@i7 ~$ iotop -b | grep Total
Total DISK READ: 16.22 M/s | Total DISK WRITE: 11.08 M/s
Total DISK READ: 14.20 M/s | Total DISK WRITE: 9.05 M/s
Total DISK READ: 14.89 M/s | Total DISK WRITE: 4.66 M/s
Total DISK READ: 43.21 M/s | Total DISK WRITE: 39.24 M/s
Total DISK READ: 31.01 M/s | Total DISK WRITE: 1994.15 K/s

Bit all over the place during the rsync. This could be my fault.


Er, wtf? Only 871GB availible from 1024GB?? 153GB has gone missing! 61GB has gone missing compared to xfs/reiserfs!!

/dev/sdb1 on /mnt/home type ext3 (rw)
/dev/sdb1             917G  200M  871G   1% /mnt/home

And there is nothing on the damn disk. Wtf is that 200M all about?

Quite a stable-ish:

Total DISK READ: 48.16 M/s | Total DISK WRITE: 45.55 M/s


/dev/sdb1 on /mnt/home type ext4 (rw)
/dev/sdb1             917G  200M  871G   1% /mnt/home

Maybe better performance than ext3. Hard to tell.

Total DISK READ: 56.90 M/s | Total DISK WRITE: 56.94 M/s


/dev/sdb1             917G   72M  871G   1% /mnt/home

Funny notes

Surprisingly sudo cp -r /home/ /mnt/home/ seemed slower than sudo rsync -art /home/ /mnt/home/. Wtf is up with that? I think rsync cleverly launches threads to speed up it's checksumming operation.

I just took a random iotop reading which I thought was representative of the transfer rates I was seeing.

For more details on the hardware please view Linux i7 rig.

Tried out xfs

So two disks with the same data from a sudo rsync --delete -art /home/ /mnt/home/.

/dev/sda4             130G   90G   35G  73% /home
/dev/sdb1             932G   99G  833G  11% /mnt/home

Ummm, wtf does the xfs drive take 10% more?

Now the 1TB is using ext4

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