Dismal performance - Software Raid

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06-09-2008, 04:02 PM
kokhong

Dismal performance - Software Raid

I had been testing DSS lite on 2 different hardware and seems to be getting dismal performance of around 2% of GbE when transfer a single 1Gb file from a T60 with GbE connection on XP-SP2 to the iSCSI volume. When transferring to the NAS share, the network bounce between 2%~14%.

Platform 1
Celeron 2 Ghz with 1Gb RAM on i945 mini-itx with 2x Marvell GbE. NAS and iSCSI Volume in RAID5 - 4disk array (4x 250Gb, Seagate/Maxtor)

Platform 2
Celeron 420 with 1Gb RAM on Supermicro PDSMi-LN4+. NAS and iSCSI Volume in RAID0 - 2 drive array (2 x 250Gb, Seagate).

I'll likely swap the Celeron 420 with a X3210 Quad-core just for comparison. Likely to get the 3ware 9550 later.

At 2% of GbE, the transfer rate is only around 2~3 Mb/sec. That's shockingly slow. Is that the normal performance of Open-E? Or am I missing something here??? :confused:

I would expect any standard linux distro to be able to handle 20~30 Mb/sec ie 20~30% of GbE bandwidth and a dedicated distro like Open-E to be able to reach 40~50 Mb/sec for RAID0 volumes.
06-09-2008, 05:03 PM
To-L

hi kokhong

you should be getting better performance than that
do you have write back enabled, also check cache size
are you using hardware or software RAID?
06-10-2008, 07:52 AM
kokhong

Hi Torpedo,

I've changed some BIOS settings, selected Enhance SATA and Intel RAID and found that the system was much faster, able to reach between 20%~30% of GbE for iSCSI. That's a more respectable 30Mb/sec for a 2 drive software RAID0. Not fantastic, but useable.:)

I'll try out a 4 drive RAID5 configuration before sourcing for the 3ware 9550. Hope that would be able to push the performance closer to 60Mb/sec. That would make disk-to-disk backup more reliable.

Thanks,
Kok-Hong

Quote:

Originally Posted by Torpedo ray

hi kokhong

you should be getting better performance than that
do you have write back enabled, also check cache size
are you using hardware or software RAID?
06-13-2008, 01:49 PM
beng

Ummm... hate to be pedantic but 30% of a GbE is 300Mbits/sec which is actually a pretty good speed :-) especially for iSCSI.
Cheers Ben.
06-18-2008, 04:59 AM
kokhong

Hi Beng,

That may be so...but gathering benchmarks figures for the 9550SX, it seems possible to get 200~300 Mb/sec for RAID5 volume. In light of that, a 40Mb/sec iSCSI performance seems to suggest that there's a lot of headroom for performance tweak.

I've used IOMeter, Intel NASPT to get the 40+ Mb/sec readings for RAID5 iSCSI/NAS reading. It would be great if others can share their experience with configuring the 9550SX for best performance with Open-E.

Quote:

Originally Posted by beng

Ummm... hate to be pedantic but 30% of a GbE is 300Mbits/sec which is actually a pretty good speed :-) especially for iSCSI.
Cheers Ben.
06-18-2008, 11:38 PM
beng

G'day Kok-Hong,
I'm just a little confused here, in one paragraph you state:

Quote:

Originally Posted by kokhong

able to reach between 20%~30% of GbE for iSCSI. That's a more respectable 30Mb/sec for a 2 drive software RAID0.

So the implication is that you are getting 20-30% of 1000 Mbit/s or 200-300Mbit/sec, but the next line you stated 30Mb/s so I assumed you meant 30MB/s(30MBytes or 240Mbits/s), which in my limited experience is pretty good for a 2 Drive Raid 0....

I don't use the 9550, or Onboard Raid for that matter, but I can say that I get around 160-180 Mbit/s Read with an Adaptec 5805 in Raid 5 with 3x Seagate 500GB.

Cheers Ben.