Robroy - ZFS Write Cache

Kris and Allan,

I've heard that when ZFS is backed by storage systems with their own write cache, such as normal SAN storage arrays, failing to disable that cache can lead to ZFS corruption.

What I'm curious about, is what makes ZFS different from other filesystems in this regard.

I understand that if write cache content's lost, any filesystem's idea of what's on the disk, and what's actually on the disk, may be at odds.  Yet this situation's not deemed risky enough with traditional filesystems to warrant disabling the write cache.

Also, if an array won't allow write cache to be disabled on a per-LU basis, and one's not willing to disable the write cache for the whole array, should the array simply not be used for ZFS?  Are there other alternatives?

Thanks to the Mega Max,

Robroy