MTU Size

[ESXDevil]

Hi

I have a question about MTU Size but first i will explain you our environment.

We have 6 HP DL380 G5 Servers with ESX 3.5 (110268) and Qlogic iSCSI HBA's (ql4052c and gl4062c)

Our Storage is an iSCSI EqualLogic Box. (1 SAS and 1 SATA Box)

We have also 2 dedicated Cisco 2960 Switches for the iSCSI traffic.

Now to my question:

Do i have to set the MTU Size also on the ESX Servers (vSwitch) and perhaps also on the VM's even when i have an MTU Size of 9000 on the HBA's, the Switches and the Storage?

When if so, how to perform that?

Thanks in advance

[depping]

yes you would have to although it's still not supported for iSCSI at this moment, I wrote an article about how to: http://www.yellow-bricks.com/2008/01/03/what-about-those-jumbo-frames/

Duncan

My virtualisation blog:

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[ESXDevil]

Thank you very much depping!

Can i change the vSwitch MTU Size on production environment or do i have to shut down the VM's (or VMotion to an other host).

Regards

ESXDevil

[depping]

I wouldn't take the risk, just vmotion them off...

Duncan

My virtualisation blog:

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[RParker]

> Can i change the vSwitch MTU Size on production environment or do i have to shut down the VM's

Yes you can, and no you don't. (Production is fine you won't lose the connection, you can even do it via putty from command line. VM's don't need to be shut down first)