Comments on: VMware over ISCSI storage – Equal Logic

By: craig

craig — Fri, 29 Jan 2010 16:31:11 +0000

When you bought a switch about this, you are talking about 2 different layer of switching. 1 is for the normal ethernet switching which serve the network file transfer purpose. Another layer of switching is specified for ISCSI SAN which connected to your MD3000i. For the ISCSI switch, you will need to go for the ISCSI optimize switch, which you can consider DELL PC5424 and you need to enable all the functionality and jumbo frame. For the ESX host file transfer, it is depending the Ethernet transfer rate as well as the ISCSI SAN performance both.

By: Kenny

Kenny — Fri, 29 Jan 2010 02:36:03 +0000

Raid 5 + 1hotspare.. I am kind of giving up already.. researched and tried over 50 different settings. The best cross esx hosts file transfer rate is less than 20Mb/s. I even bought a new Netgear GbE managed switch for the SAN subnet..

By: craig

craig — Tue, 26 Jan 2010 16:33:34 +0000

Which raid configuration you are using?
Raid 5? or Raid 6? or Raid 10?

By: tstkenny

tstkenny — Mon, 25 Jan 2010 14:53:55 +0000

Yeah I am sure that jumbo frames are enabled on physical, virtual, and md3000i, ‘cos I can do a vmkping -s 8991 to the private network the md3000i from any of my ESX hosts.

When I conduct the test, the ESX hosts have no uplink. i.e. on the switch, there is almost zero traffic except the ESX host itself. And there is only one VM running: the ms2003 server with Trilead installed.

I also tried IOMeter. With 32k, 100% read, sequencial, IOMeter reports around 100Mb/s throughput. With 32k, 50% read 50%write, 100% random (which is more likely a file server traffic looks like), the thru’put down to like 10Mb/s.

I suspect that there is something I can tweak on the MD3000i CLI about the write buffer?

I really want to know the Trilead speed of others.. 20Mb/s copying files is nightmare…

By: craig

craig — Fri, 22 Jan 2010 16:24:33 +0000

20MB.s is not normal. When you talk about jumbo frames enable, you need to ensure it turn on from the physical switch level, virtual switch level and storage controller itself too. We are using Intel gigabits NIC and broadcom mix in the case we mentioned. Beside that, when you use trilead, if I not mistaken, it will transfer the images through Network, that will depend how was your bandwidth can go from each ESX host on the LAN itself. you can try to perform a cold migration again and capture the performance from the vcenter again.

By: Kenny

Kenny — Fri, 22 Jan 2010 08:00:24 +0000

I have almost the same hardware config and did turn on all Jumbo frames. Since the performance tab on the VI is aggregation, I setup the following test instead:

1. install the free VM Explorer (from trilead.com), install it on a Win2003 VM.
2. copy a file from R710 local storage (which is a SAS 15k here) to MD3000i a simple 20GB LUN.

VM Explorer has a run time speed meter while copying files across ESX hosts. And it shows.. 20MB/s the max… :_(

I tried every combination I can think of like: MRU, fixed path, round robin. No improvement and sometimes degration.

I really want to know your MD3000i to ESX 4 hosts on Dell R610/710 using the on board broadcom GbE nics..

If 20Mb is normal.. I think I bought the wrong SAN then ;p

By: craig

craig — Mon, 25 May 2009 08:18:43 +0000

Hi Albert Widjaja,

you may want to read my latest post, which regarding the md3000i performance tuning, that will help your case

By: craig

craig — Mon, 18 May 2009 06:48:34 +0000

I heard the vsphere had improved from the Software ISCSI initiator point of view. Should available for download sometimes next week. you may want to try it out

By: Albert Widjaja

Albert Widjaja — Mon, 18 May 2009 02:29:54 +0000

ok, now that does sounds very great testimonial from the Storage expert like you Craig

total full performance comes with a price tag.
therefore I can confidently conclude that with the MD3000i dual controllers, only one that is actually used for data transfer (not both to boost performance).

Combined with the limitation of iSCSI software initiator from the ESXi, by default MPIO is used here for providing link redundancy without the implementation of managed switch to perform VLAN trunking (LACP)

That is all my conclusion to maximize the current investment that i’ve made.

hope this can be a helpful resources for you.

Cheers,
Albert.

By: craig

craig — Mon, 18 May 2009 02:08:44 +0000

you can also try the IO meter to run your I/O test on Virtual Machine