Bad Performance with SCSI 320 - DELL PERC320

Message

COiN3D · Post by **COiN3D** » Fri Mar 07, 2008 4:19 pm

Hi all,

I've somehow a problem with the performance of a SCSI-RAID Controller called "DELL PERC320", which is an 64 Bit-Adaptec 2200 RAID SCSI Controller AFAIK. There are 4x SCSI 10k Ultra-320 Harddisks connected to the RAID controller and they get recognized by it fine, and all the four hard drives are bound to a RAID5 array.

First of all I've to say that I didn't try it with Gentoo yet, but with Knoppix. Before I booted Knoppix the first time, there was installed Windows Server 2003, all I wanted to do was to zero out the whole disks with "shred" - after a while I recognized that the access was embarrassingly slow, and so I tried it with "dd if=/dev/zero of=/dev/sda" - and cancelled this process after a few seconds again. DD showed a transfer rate of 22MB/s, which is, imo very slow for a high end raid controller with 4x 10k rpm discs. After that I removed the RAID and tested the disks apart - but dd also showed very slow transfer rates of about 28MB/s.

What do you think is wrong with my system? Is it the hardware? Or is it just a bad kernel driver from Knoppix?

Thanks in advance.

theotherjoe · Post by **theotherjoe** » Fri Mar 07, 2008 5:09 pm

28MB/s seems pretty poor to me. You do not use
disks from 1998 so somthing, do you?

)
For easier comparison you may want to run bonnie
benchmark or try hdparm -Tt repeatedly on any of
your disks to get some more number about the
throughput.
Maybe scsi driver not in synchronous mode, just a guess though.
have a look at your log messages

COiN3D · Post by **COiN3D** » Fri Mar 07, 2008 9:57 pm

theotherjoe wrote:28MB/s seems pretty poor to me. You do not use
disks from 1998 so somthing, do you? )
For easier comparison you may want to run bonnie
benchmark or try hdparm -Tt repeatedly on any of
your disks to get some more number about the
throughput.
Maybe scsi driver not in synchronous mode, just a guess though.
have a look at your log messages

No, all four hard drives are, okay, lets say quite old (from 2003 afaik) but with SCSI 320 Interface and 10k RPM.

Isn't hdparm only for ATA-devices, is it? And thanks for the synchronous tip, I'll check it on monday, when I'm back in work

COiN3D · Post by **COiN3D** » Mon Mar 10, 2008 10:34 am

Okay, the performance problem is definitely caused by KNOPPIX - I've just put in a Win2k3 Server CD and load the original drivers. When I formatted the disk with NTFS (full format, with "fill-zero") the whole format process finished in about 2 minutes (300 GB, RAID 10)....