hardware RAID-5 - too slow transfer!!!!

wbodzek · n00b Joined: 09 Nov 2004 Posts: 3

Motherboard: Tyan Thunder K8S Pro
CPU: 2 x Opteron 1.6GHz
Hardware Raid controller (lspci shows):
0000:01:01.0 RAID bus controller: 3ware Inc 3ware Inc 3ware 9xxx-series SATA-RAID
connected:
3 hard disk of 186GB in RAID-5

I installed Gentoo/AMD64 on it. I have /dev/sda as this RAID controller, here comes LVM2
and I have about 15 volumes on it.
The thing i'm confused is that:

server / # hdparm -T /dev/sda
/dev/sda:
Timing cached reads: 3512 MB in 2.00 seconds = 1754.51 MB/sec

server / # hdparm -t /dev/sda
/dev/sda:
Timing buffered disk reads: 74 MB in 3.06 seconds = 24.20 MB/sec

Cached Timing is very fast, but normal is too slow for me.
Anyone knows how to speed up this transfer?

PrakashP · Posted: Wed Feb 23, 2005 2:39 pm Post subject:

Is a partition with fs on the device? Sometimes hdparm shows low values if the device is blank.

Primozic · Posted: Wed Feb 23, 2005 4:21 pm Post subject:

Have you tried this?

wbodzek · n00b Joined: 09 Nov 2004 Posts: 3

Yes, now whole Gentoo is installed on it, with about 15 volumes in LVM2 so it isn't blank.

Next thing. After executing
blackdev --setra 16384 /dev/sda
transfer grew to about 50MB/s, but it still isn't that I want.

One thing more... I compiled support for my RAID controller to kernel not as module...
I don't know if it is important...

Chaosite · Posted: Wed Feb 23, 2005 6:36 pm Post subject: