Jay Orr writes:
Here's a question - we had to replace some parts in our F330, and ended up only putting 2 of the 4 simms from the NVRAM card back onto the card. What kind of performance does more/less NVRAM have on a filer?
There's the obvious issue (as previously discussed) about performance dropping due to less NVRAM to buffer requests up.
Also, (if I recall correctly), NVRAM is slower than normal RAM, so memory interleaving is used to speed up NVRAM writes. I'm not sure if the NVRAM supports 2-way interleaving, or if interleaving only kicks in when you have 4 SIMMs installed (giving 4 way interleaving).
Maybe one of the NetApp engineers can comment further; this is working from hazy recollections when I was advised that upgrading our F330's from 2MB to 8MB would have a significant performance improvement due to the lack of capacity of the 2MB NVRAM and the lack of interleaving.
Luke.