iscsi slow in Virtual servers

[kevin@nextvault.com]

Here is our environment:

Windows 2008 server running latest version of Starwind.
Has multiple targets both disk and image and several servers connecting to it via separate storage-only LAN.
WE created a new ESX Server and loaded a WIndows 2008 guest OS. Using MS Iscsi initiator connected to a disk target on the above Starwind server no problem. We can access the drive, format it, etc with acceptable performance.
But....
When we reboot the Guest OS server the iscsi intiator sees and connects to the drive very quickly, but when we pull up Windows Disk administrator it takes hours (literally as much as 8 hours) for it to see the new drive, then takes 8+hours to quick format.
We experience the same problem of the Windows Guest OS seeing the drive and using it after reboot (after all formatting is complete) for about 8 hours, then it seems to function and drive performance is acceptable.
We can reproduce this problem on 2 different host systems, one running ESX, one running VMWare server.
The length of delay seems to relate to size of the disk image (5GB image takes less delay than a 500GB image)
We can connect to the same targets without performance problems from any physical machine with the same configuration (separate lan and storage networks)
We don't see any error messages anywhere.
We've checked cabling, switch settings (even change switches), used different NIC interfaces...nothing seems to help this.
Hoping someone can share if they have had similar experiences or other things to check...or a solution!
Thank you

[georgep]

I do have the same issue. With windows initiator it`s fast .. from VMware ESX VM is slow...

[Anatoly (staff)]

Have you seen this?

Also, have you disabled Delayed ACK?

[kevin@nextvault.com]

Thanks for the links and suggestions.

We are not using MPIO or NFS on the HOST system at all so that does not seem to be part of the problem.
WE disabled ACK, no change

The problem seems to be able to replicate on both a ESX host system and a Windows Host system runninge VMWare Server.

Any other insight would be greatly appreciated.

Thank you

[anton (staff)]

Good. So at least some of the possible issues are isolated and checked for being non existing. Could you please provide remote access details so our engineers could check what's wrong w/o disturbing you? Thanks!

Thanks for the links and suggestions.

We are not using MPIO or NFS on the HOST system at all so that does not seem to be part of the problem.
WE disabled ACK, no change

The problem seems to be able to replicate on both a ESX host system and a Windows Host system runninge VMWare Server.

Any other insight would be greatly appreciated.

Thank you

[kevin@nextvault.com]

Hi Anton
terrific offer. These are production systems so we need to team up to do this, but I have a tech who is able to schedule a remote session.

Can you email me the appropriate contact info and I will have my tech make arrangements with them?

On a side note, we setup a brand new install of Starwind on a different server and we don't seem to be experiencing the problem in this test case.

So it seems to be related somehow to a system that has been through the upgrade paths of Starwind. The good thing is that your engineers can compare the two systems and hopefully will very quickly see what is happening.

Thanks!

[Anatoly (staff)]

Just email to Support@starwindsoftware.com describe your issue and mention this topic in your email please.

Thank you

[sunyucong]

is there a solution here?

[kevin@nextvault.com]

Hi sunyucong

We have been working with their engineers directly offline of this forum and at the moment have not had any progress.
Are you having the same problem?

[Constantin (staff)]

Can you provide me with some info about your hardware?

[DDiClaudio]

We are experiencing the same issue with a fresh install of Starwind on a fresh Windows 2008 R2 install.
We have two ESX hosts and the iSCSI performance is terrible (maxes out at 35ish MB/sec).

The hardware is new and is capible of much faster transfer speeds. I have six 1 gbit interfaces teamed on the storage server using 802.3ad LCAP, and I have 4 physical NICs teamed in ESX using IP Hash as a 802.3ad Static LAG.

Jumbo frames are enabled and all my vm Traffic is super speedy... just not iSCSI.

I'm currently evaluating StarWind, I like the software, but the speeds are very slow. I use Openfiler in my home ESX lab and I get much better iSCSI speeds. I've followed all the guides on the StarWind site but have not been able to increase the iSCSI throughput.

Has the topic of this post been identifed and resolved? If so, what was the resolution? I need to resolve this soon or we will be unable to purchase the software.

[bill@nextvault.com]

Hardware/Software for Virtual Machine:

Windows Server 2008 Standard 32 bit (virtual on VMWare server)

VM HArdware specs:

(1) Intel Xeon 5140@2.33GHz
2GB RAM
Two NICs (Intel PRO/1000MT) separate for LAN and iSCSI

[kevin@nextvault.com]

We are still troubleshooting with Starwind, we had to put the troubleshooting on hold while we moved our live customer to a dedicated box so that our testing would not impact their performance. oddly we have one machine we setup with a fresh install that works just fine. So, we don't know what the differences are. We are working with their engineers how to see if we can best figure it out. Stay tuned as we will update this thread as we have progress.

[Constantin (staff)]

Keep us posted plz.
Also if you would continue with testing on ESXi VM - send us an email to support@ with attached Visio scheme how StarWind VM access the network - proper configuration of vSphere is pretty important.