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queensbridgeitt
Contributor
Contributor

2 File servers in ESX4. Backups slow on 1 VM...Why? Network card issue?

Hi

I was wondering if someone had any advice with an issue I are having with backups of 2 file servers running as Virtual Machines. Both machines are VM’s in a ESX4 cluster running esx4.0.0 update 2 and are configured as follows:

2003 server - 4 vCPU's and 4gb RAM, it is a 32bit server with the flexible network card in VMware.

2008 server 1vCPU 64bit server with 3gb RAM with the E1000 network card in VMware.

1 file server is a Windows 2008 R2 Enterprise server which has approx 450gb of data and

the other file server is a Windows 2003 R2 Enterprise Server which has approx 450gb of data.

To do a full backup on the 2008 server it takes a reasonable time of 9 hours but the 2003 server is taking nearly 19 hours do backup the same amount of data.

When I look at the logs on the backup server to measure the throughput is vastly different.

It is reported that the 2008 has a throughput of approx 51000.000 MB/Hour but the 2003 server only has a throughput of 23000.000 mb/hour.

I thought it could be something like the antivirus running at the same time as the backup. It was indeed running but since I have disabled this it hasn't made a difference in terms of the throughput.

I have read that it could be the network configuration on the VM's. The 2008 server is using the E1000 adapter which I know provides much better performance than the flexible adapter. The 2003 has the flexible adapter, this VM was originally a P2V migration and I think by default ESX4 gives the flexible adapter as the most compatible adapter for a VM.

I was thinking of changing the adapter on this slow server from a flexible one to either the E1000 or one of the VMXNet adapters. Are there any thoughts on this. I hear if i use the VMXNET3 adapter it simulates a 10gbps adapter in the VM even though we may only have a 1GBPS adapter actually running. Has anyone seen any issues with this? I hear that this adapter will provide the best throughput and is compatible with the 2003 R2 Enterprise server I am running.

Any suggestions would be greatly appreciated.

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mjpagan
Enthusiast
Enthusiast

I would change the virtual network card in your slow VM. This article has the vnic card drivers detailed and I would changed it to the VMXNET3to see if you get better results.

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=100180...

Mike P

MCSE, VCP3/4

Mike Pagán MCITP:EA, MCSE, VCAP5-DCA, VCAP5-DCD,VCP 5, VCP5-DT, CCNA, A+
queensbridgeitt
Contributor
Contributor

Thanks for the reply. When I remove the old flexible adapter, is there any point me using the same MAC address on the new VMXNet3 Card or am I best letting the new NIC use a different MAC address?

Thanks

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