Slow performance

[ksuchewie]

Currently I have 2 ESX servers running off an EMC AX4 through ISCSI. I backup these VM's to another ISCI device, an EMC AX150i.

The speed of the VM's is good, so I don't think there's anything wrong with my AX4.

However, when I backup my VM's to my AX150i, I usually see write speed of about 9 MB/sec. So my backups take FOREVER. I have looked around and a lot of fingers are pointed at network config.

My network:

I have a seperate ISSCI vlan. The only devices that use this vlan are the EMC ISCI connectors (the storage processor management NICs are on a seperate vlan), the ISCI ESX server ports, and the esxpress backup agents. I have a seperate vlan for vmotion. All NIC cards / switch ports are labeled at 1000/FULL, not autonegotiate.

I have my esXpress backup target (ax-150i) ISCI connected to a HP DL-360 via iSCSI.

any ideas / help?

[Rodos]

Could be lots of things. Just because the AX4 runs okay under normal load of the VMs does not mean it is running well under the load of backup. How many spindles do you have. If you are trying to write a lot of data very quickly to an AX150 with few spindles its going to choke quickly.

When you look at your performance monitoring tools (even vCenter Server, esxtop, CLI on ethernet switches) where are the bottlenecks.

You say you have a different vLAN for iSCSI, does that mean you are sharing the same physical ports, you have just segmented the traffic? If its reading out of one SAN and then writing it off to the other and the two flows end up hitting the same ASIC on the some low end switch then yes its going to go slow.

Draw out all the traffic flows and write on them their expected peak throughput and then what you are measuring. That should reveal where you can make improvements.

Report back too, others may benefit from your findings.

Rodos

Consider the use of the helpful or correct buttons to award points. Blog: http://rodos.haywood.org/

[ksuchewie]

My AX4 is full (12) of 400GB 10K SAS drives.

My AX150i has (5 ) 500GB 7200 SATA drives.

[Rodos]

Well I don't think the word performance can be used anywhere near 5 x 500G 7200 SATA drives. Whats the expected write throughput on that? Someone here may know or you can do some performance tests yourself, do you have any write cache. Once you know what to expect you can see if the backups are running as fast as they can because the SAN is the weak link or if you need to dig into something else.

Rodos

Consider the use of the helpful or correct buttons to award points. Blog: http://rodos.haywood.org/