DSS on VM hosted on ESX 4.1 Slow Performance

Hi,

I have DSS installed on a Virtual Machine running under ESX 4.1. 200 GB VMDK is presented via the ESX DataStore. 1 Target and 2 Vol Group created and presented to the ESX as an iSCSI Target. Formatted as VMFS and hosted 1 Windows 2k3 VM. I tested copying file locally inside the VM is very slow and gives me speed of 2.3 or 1.8 MB/s. Wherein if I move this VM locally to the same ESX Datastore and start to copy files locally I get 35 ~ 48 MB/s.

DSS is installed with 3 GB memory and 2 vCPUs.

What could be the issue and how can I achieve high read and writes?

Thanks,

What is your build of DSS that you are using?

It could be that you need some tuning, try :

maxRecvDataSegmentLen=262144
MaxBurstLength=16776192
Maxxmitdatasegment=262144
FirstBurstLength=65536
DataDigest=None
maxoutstandingr2t=8
InitialR2T=No
ImmediateData=Yes
headerDigest=None
Wthreads=8

Also to change the Jumbo frame:
http://kb.open-e.com/Does-Open-E-sup...Frames_28.html

This changes should be made to each target.

Try also to check your initiator settings, even if you have to remove all settings and create them again.

hello,

I'm using 6.0up50.8401.4786 32bit. I have tried these settings as I have found them in one of the thread in this forum. But nothing helps. Jumbo frames enabled in the ESX vSwitch. I will try the jumbo frame on the DSS site and let you know..

Thanks,

Quote:

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Originally Posted by habibalby

hello,

I'm using 6.0up50.8401.4786 32bit. I have tried these settings as I have found them in one of the thread in this forum. But nothing helps. Jumbo frames enabled in the ESX vSwitch. I will try the jumbo frame on the DSS site and let you know..

Thanks,

---

for jumbo frames to work, it must be enable along the entire path.

Hi,
I have enabled it and rebooted the DSS, still same issue. Copy started at 5.5 MB/s and ended up on 1.7 MB/s :(

Can you test with the latest version and select 64bit mode instead of 32bit?

I will try that.. Thanks for this suggestion. will reply to you once it's done..

Hello,
I have tried that, it gives same problem.. Today I'm going to try NFS on windows 2008 32bit and compare the performance.

Any suggestion, please feel free..
Thanks,

On the ESX server where the DSS V6 is installed what is the system RAID settings to be sure that the ESX is tuned for Write cache and other settings.