Slow Network Performance - Slow after 3GB

[samuk]

Hi,

I have setup a test Lab, consisting of:

• 2 Lenovo Servers - with ESX 5.5
• 1 HP G8 Micro Server with a P410 raid controller and 4 2TB SATA Drives in RAID 0  - with Windows 2012 Storage Server

I have enabled Jumbo frames on the Micro Server MTU Value 9014 - this nic is on a separate Network and switch

On the ESX host, i have used a nic for ISCSI traffic, assigned to the ISCSI network and separate switch.

The MTU of the switch is set to 8000 - anything more if does not see the ISCSI disk

Tests

I am copying a 4GB ISO file from a VM that is on the local ESX Servers Disks to a VM located on the ISCSI Datastore

3.5GB copies at 100MB/S, then the network drops to 0% and file copy time remaining goes from 60 seconds to 10+ mins and it just stops.

Reading from it is fine.

I have copies the same file to the D drive of the storage server (by passing ISCSI) - same thing happening.

Almost as if Network buffer of something runs out..?

Really stuck, any help appreciated.

Sam

[brunofernandez1]

what kind of OS are you running on the VM?

what network card do you have installed on the VM? e1000 , vmxnet?

[samuk]

Windows 2008R2 witn VMXnet3  - 6 GB RAM

I can now copy to the Storage Server D driver across the network fine near 50MB/S

so the issue is VMware related...

Network utalisation goes to 0% after few GB of burst of 100+MB/Sec to a VM Datastore

The advance Network options for the ISCSI in ESX are not making sense to me..is it worth making some changes there?

[brunofernandez1]

your storage provider will probabelly have some whitepapers how to configure the storage for esx server.

maybe this could help.

you could also try to use the e1000 network card. there could be an issue with the vmxnet network card.

[samuk]

Should i have TCP options checked

QoS & File & Print Sharing?

[brunofernandez1]

on the network card? yes please

without TCP you aren't going to do quite nothing on the network 😉