Hi toasters,
we have just recently "upgraded" our netapp infrastructure and moved from lots of small FC drives, to a much smaller number of SATA drives. We knew this would cause a performance decrease and compensated by installing 512GB flexcache cards. Its a HA 3170A.
So far it all kind of works. However, its clear that the caches take a long time to heat up, several hours in fact. During that time, performance is "average" to say the least.
So, I guess I have 2 questions for people who are doing similar things:
1) are there any tips on ways to improve the cold start performance (I cannot think of any). 2) if I have a HA failover, I imagine my performance will be even worse since the second heads cache will be completely cold for the data from the failed head and to make things worse, the second head will have to eject data from the cache for its own local volumes. Anybody with experience of this? 3) Any bright ideas other than more spindles?
It would be nice if the caches were nvram, to avoid the cold start problem. I really netapp should use SSD's for the cache for exactly this reason. Or am I missing something?
Regards, pdg