Jumbo Frames on NIC in VMware
Do I need to enable Jumbo Frames on the dedicated iSCSI NICs in VMware?
I have configured the MTU on the Dell SCv2020 SAN, Dell N3024 Switches, vSwitch1 and 2, but when I try to configure the NIC with MTU of 9000... This is the error I receive.
If I flip the MTU on the NIC dedicated to the iSCSI connections back to 1500 then I can see all the LUNs and Datastores. I have reviewed this document too.
https://www.experts-exchange.com/articles/9132/HOW-TO-Enable-Jumbo-Frames-on-a-VMware-vSphere-Hypervisor-ESXi-5-0-host-server-using-the-VMware-vSphere-Client.html
The NICs for this Host are: Broadcom Corporation NetXtreme BCM5720 Gigabit Ethernet.
Thanks!
I have configured the MTU on the Dell SCv2020 SAN, Dell N3024 Switches, vSwitch1 and 2, but when I try to configure the NIC with MTU of 9000... This is the error I receive.
If I flip the MTU on the NIC dedicated to the iSCSI connections back to 1500 then I can see all the LUNs and Datastores. I have reviewed this document too.
https://www.experts-exchange.com/articles/9132/HOW-TO-Enable-Jumbo-Frames-on-a-VMware-vSphere-Hypervisor-ESXi-5-0-host-server-using-the-VMware-vSphere-Client.html
The NICs for this Host are: Broadcom Corporation NetXtreme BCM5720 Gigabit Ethernet.
Thanks!
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ASKER
Yes I am using the software iSCSI Adapter. I have confirmed everything is running at 9000 MTU.
SAN
SWITCH
vSwitch
but the moment I switch the MTU on the vmNIC dedicated to the ISCSI it can't see any LUNs/datastores. I checked the BCM5720 and it does support Jumbo Frames.
SAN
SWITCH
vSwitch
but the moment I switch the MTU on the vmNIC dedicated to the ISCSI it can't see any LUNs/datastores. I checked the BCM5720 and it does support Jumbo Frames.
ASKER
Let me check one more time since your update Andrew.
vary the size of the MTU, 4000, 8192, 9016, etc
a jumbo frame is defined as any frame larger than 1500 (approx!).
there is not really any standard.
you can also test your network using vmkping.
see here
https://communities.vmware.com/message/2418768
http://rickardnobel.se/troubleshoot-jumbo-frames-with-vmkping/
http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1003728
a jumbo frame is defined as any frame larger than 1500 (approx!).
there is not really any standard.
you can also test your network using vmkping.
see here
https://communities.vmware.com/message/2418768
http://rickardnobel.se/troubleshoot-jumbo-frames-with-vmkping/
http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1003728
ASKER
ASKER
I will start running through those documents Andrew and see what I can find.
make sure the VMKernel iSCSI Fault Domain is also 9000, and not defaulting and set to 1500!
also most Dell storage switches we've seen 9000 are the default, but just check the individual ports!
also most Dell storage switches we've seen 9000 are the default, but just check the individual ports!
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that's odd we use 9000 on out ESXi nics, and the switches are set to 9216!
and we also use Dell switches!
and we also use Dell switches!
I belive switches MTU need to set a bit higher compare to client for overflow.
ASKER
This was the fix after working with Dell Enterprise.
Check your SAN and Network settings.
Make sure ALL the VMKernel Portgroups are 9000, and also the main vSwitch is 9000.