On Tue, Jun 02, 2009 at 09:26:17AM -0700, Steve Francis wrote:
You can get a performance boost by splitting it up. Which is why I don't like to do that, in general, for performance sensitive workloads. :-)
Otherwise, in the event of a head failure, the surviving head may not have the CPU/cache to deal with the extra work - even if both heads are normally under 50% load. Most workloads grow linearly - until they hit an elbow an don't grow linearly. The only true way to be sure you have failover capacity is to run that way all the time.
Your mileage/budget/workload/performance requirements may vary.
Thanks all. Great advice. So, my question is: if the second head can take over the personality of the failed head, why do I need to allocate any disks at all to the second head to begin with? Just a design thing?
I'll probably do the even split thing.... and look into ordering additional NIC's.
Can I have a "spare" that is available to either aggregate on either filer? This way I could do two RAID-DP's on each head with one common "spare" disk and rely on 4hr support to get me replacement disks quickly.
Ray