hdparm: 500, 200 and 20MB/s as results, within seconds?

1

No, nothing is running on the server.

[root@~]# hdparm -t /dev/sdb

/dev/sdb:
Timing buffered disk reads:  1672 MB in  3.00 seconds = 557.18 MB/sec
 [root@~]# hdparm -t /dev/sdb

/dev/sdb:
 Timing buffered disk reads:  770 MB in  3.00 seconds = 256.66 MB/sec
[root@~]# hdparm -t /dev/sdb

/dev/sdb:
 Timing buffered disk reads:  116 MB in  3.08 seconds =  37.61 MB/sec

What is happening?

I have 10 * 1TB disks in hardware raid 10 (512MB cache, LSI MegaRAID SAS 9260-4i)

cedivad

Posted 2011-10-19T16:37:19.183

Reputation: 292

need Input, what is the motheboard, what are the drives? and what is the video card? . . . . did you try aiming extra cooling at the card? – Psycogeek – 2011-10-19T17:24:17.843

1

i don't think to have a video card! Here are all the info i have on my server: --- http://www.ovh.co.uk/dedicated_servers/hg_2011_technique.xml --- Drives are Seagate Constellation ES --- is the card (raid card) too hot in your opinion? :|

– cedivad – 2011-10-20T11:50:41.920

I have no idea, was trying to think of any reasons, like reduced PCI-E link Negotitions (1 lane instead of 8) Specific drive items, that some users found to work for 1-2 then slow down after adding more. Possibility that the heatsink is poorly mounted and thermal gooped. and lastly that the card itself just isnt the greatests. What you have so far looks like blazing speed until the ram Caches all run out :-) then your back to reality. – Psycogeek – 2011-10-20T12:10:53.200

1i've tried an hdparm with a raid 1 ssd array, (always trough the raid card), results: 250.41 MB/sec///252.62 MB/sec///252.61 MB/sec --- so i think the raid card not to be the problem, maybe the problems only comes out with 10 disks in raid 10... :| – cedivad – 2011-10-20T12:43:03.633

No answers