I have a couple of questions regarding the ZFS page cache that I haven''t seen addressed anywhere else and I''m sure will be quick for the experts to answer. - Is it possible to turn off the page cache for a ZFS filesystem using a mount option similar to forcedirectio on UFS? - Does the page cache exactly mirror what''s on disk or is it optimized for performance? In particular, is checksumming performed whenever data is read from the cache or just when it is read from disk? If the data on disk is compressed, is it also compressed in the cache? - How does the ZFS cache interact with other filesystem caches? If all of the memory on my system is either in use by applications or is caching data from one or more UFS filesystems, then will accesses to files on a ZFS filesystem be allowed to steal memory from UFS in order to cache the new file? Thanks Neil