iscsi performance

[daobang wang]

Here is the result of the iscsi volume performance with IOZONE on windows and linux.

Linux: the iscsi volume formated the volume as ext3 with default parameters
Writer Report
64 128 256 512 1024 2048 4096
4194304 90152 99316 90032 92065 81018 85747 86212
Re-writer Report
64 128 256 512 1024 2048 4096
4194304 86036 85099 90097 87432 83687 81529 80045
Reader Report
64 128 256 512 1024 2048 4096
4194304 94822 97099 96894 97612 60799 60636 60795
Re-reader Report
64 128 256 512 1024 2048 4096
4194304 92670 97945 96336 97591 60543 60611 60505
Random Read Report
64 128 256 512 1024 2048 4096
4194304 7269 12359 17589 27667 41623 56222 65754
Random Write Report
64 128 256 512 1024 2048 4096
4194304 8905 10600 19286 33684 42681 54249 56901

Windows 2k3: the iscsi volume formated as NTFS with default parameters

Writer Report
64 128 256 512 1024 2048 4096
4194304 8560 10600 12901 8223 6298 9974 6003
Re-writer Report
64 128 256 512 1024 2048 4096
4194304 31411 36873 43424 7099 6871 9749 5928
Reader Report
64 128 256 512 1024 2048 4096
4194304 52838 55762 54605 60310 69646 48959 56039
Re-reader Report
64 128 256 512 1024 2048 4096
4194304 59710 64809 59356 67408 70002 49021 56189
Random Read Report
64 128 256 512 1024 2048 4096
4194304 7068 8140 10155 18138 28435 33137 42907
Random Write Report
64 128 256 512 1024 2048 4096
4194304 8895 6726 9790 4423 7211 9649 5374

[daobang wang]

According to the result, it's more and more better random write performance when the written date size changed from 64KB to 4MB on linux. but on windows, the random write performance is so poor, always below 10MB. Is there any operation need to do?

[To-M]

What version are you running and is there Write Back option on the LUN? Is the Write cache enabled on the RAID controller?

[Gr-R]

make sure firmware and dss are current versions.
search the forum for this:

MaxOutstandingR2T - 8
MaxRecvDataSegmentLength - 262144
MaxXmitDataSegmentLength - 262144


and make the tweaks from the console.

write back can help too.

[daobang wang]

Hi Todd, Thanks for your reply, write back option on the LUN was enabled, and what's the meaning of the Write cache enabled on the RAID controller? I used the software RAID, not hardware RAID. thanks!

[daobang wang]

Hi Gr-R, it's seems that the parameters you pointed had incorrect value, i will try it again with you suggestion, thank you very much!

[daobang wang]

Hi Gr-R, I changed the configuration parameters, the performance did not improve. Is there any other reason?

[Gr-R]

What version of DSS you using?

Is hardware RAID an option ?

[To-M]

See this link on running IO tests.

http://blog.open-e.com/a-few-practic.../#comment-4743

or run BST5 (NTFS formatted) http://www.nu2.nu/download.php?sFile=bst514.zip
Sequential 1MB for reads and writes
Sequential 4MB for reads and writes