storevirtual 4330

[phillbl1]

Hi we purchased a 2 node p4330 the other month and added it to an existing p4300 cluster.  the disks on the new 4330 are 10k drives.

we have noticed on the performance of the cluster that the total latency of all the old nodes is fine but the new one are 5/6x higher.  this would be degrading the overall performance of the cluster.

is it ok to mix these nodes?

thanks

[oikjn]

if the new nodes are running much higher latency than the old ones the new nodes ARE degrading overall performance since a write will likely go to an old node and a new node the write won't be confirmed until BOTH nodes condirm the write. 

Basically treat a cluster like a traditional raid group where the cluster will only be as fast as the slowest node and only as large as the smallest.

[phillbl1]

so i assume the best way forward would be to remove them and setup a seperate cluster?

[oikjn]

I don't know what the stats are on the original nodes to know if what you are seeing is expected, but if the HDD speeds and number of drives are similar, I would expect the nodes should perform fine as a single cluster.  I don't know how long you had the new nodes on the cluster, but it could have just been that the nodes weren't fully down their background initilizations and they just needed a little more time to get running at 100%.

If the nodes should be similar because the drives are the same RPM and similar spindle count/size, then I would be on the phone w/ support to sort out why the nodes aren't performing.

Short of that, if the slow nodes are running as they are supposed to, you should defnitely put them into their own cluster.