Hello,
I've set up a system which will be used for a file server/workstation.
It consist of a core2duo 6600 on a nvidia 680sli mainboard.
It has 4gb of ram, and ubuntu64.

I have my primary drive, a new 10krpm 300gb wd disk (don't remember it's part number, I'm sure you know which drive I mean. Besides, I'm to lazy to find out).
This has a performance of something like this:

martinn@workstation:~$ sudo hdparm -t /dev/sda
/dev/sda:
Timing buffered disk reads: 364 MB in 3.01 seconds = 121.01 MB/sec

My storage drives consist of an LVM with two drives; a Green Caviar 2tb ( WDC WD20EARS-00S ) and a Hitachi 2tb ( HDS72202 ).
Now the speed here differs _sligthly_

martinn@workstation:~$ sudo hdparm -t /dev/sdb (WD)

/dev/sdb:
Timing buffered disk reads: 68 MB in 3.01 seconds = 22.62 MB/sec
martinn@workstation:~$ sudo hdparm -t /dev/sdc

/dev/sdc: (Hitachi)
Timing buffered disk reads: 326 MB in 3.03 seconds = 107.42 MB/sec
^[[Amartinn@workstation:~$ sudo hdparm -t /dev/sdb

And of the volume group:
martinn@workstation:~$ sudo hdparm -t /dev/vg0/Data
/dev/vg0/Data:
Timing buffered disk reads: 268 MB in 3.01 seconds = 89.00 MB/sec

Both 2TB drives are on the same physical storage controller.
I see no reason why they should differ so very much?

No torrents/cron jobs is running btw.
Any and all help would be greatly appreciated;=)

PS - Of course - eager as I am, the volume is already full, and it would be painstakingly difficult to move 3,4TB of data just to test something. Move data to fix the problem - that's entirely another matter;=)

\\mK

The problem is your WD 'EARS' Green hard disk. This device causes problems (performance, throughput, even noise and head loading counts) frequently. I've looked at many threads concerning this drive and people seem to get mixed results fixing the problem.

This is odd; the problem is associated with 4k sectors, and there are people who claim that the fix is reasonably well defined, but not everyone seems to have success, or maybe only have success after terying and failing several times. For this, I cannot offer an explanation (and I don't have one of these drives, but I've been considering it out of a misplaced, ornery, 'course its easier than that' stupid sense of irritation).

http://www.linuxconfig.org/linux-wd-...dvanced-format

http://thunk.org/tytso/blog/2009/02/...se-block-size/

http://community.wdc.com/t5/Desktop/...EARS/m-p/10920

(I'd thought that there was also a Ted T'so article on 4k sectors directly, but neither I nor Google can spot it at the moment!)

2 members found this post helpful.

Aha,
Thanks a lot for intuitive information;=)
This was certainly enlightening! *phew. This means I have to move all my data again.
At my current connection speed, It'll take me 104 days at optimum performance. And my storage/backup server is 15mins away by foot. I can easily outwalk my internet line when it comes to moving data... Even if I use dvd roms to carry data.
Thanks a lot!

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