I do mean nss (as opposed to ie outdoor one)

On all my NW 6.5 SP6 (currently) servers for the last 4 years I only had
problems with a pool that is on external Dell PowerVault 220S with a size of
1.8 Tb (15 x 146 Gb drives in RAID5 config)

I never had problems with any smaller pools

Is there an optimal size that the pool should be to avoid corruptions in