I was wondering if someone had any advice with an issue I are having with backups of 2files servers running as Virtual Machines. Both machines are VM’s in the ESX4 cluster 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 it 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 VMware machines. The 2008 server is using the E1000 adapter which I hear provides much better performance than the flexible adapter. the 2003 has the flexible adapter,this server was originally done as a P2V migration and I think by default VMware 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 adapter. 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. 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.
For performance and functionality I always use VMXnet2/3, which is a paravirtualised device driver and requires VMtools to be installed.
But your issue with backup performance could be many things, such at tuning your backup client, network contention on the NIC's, VMstore performance or any other OS/Application issue