No.<p>ZFS solves 1990s era problems - nobody has filesystems that large on local disk. We use clustered filesystems for that. On SAN, GFS works nicely.<p>DTrace is good, but in practice you don't often run into problems where kernel-level tracing is required. The recent example of 'look at MySQL running SQL queries by watching printfs' could be done with strace (or for that matter MySQL in the first place).<p>Everything else Solaris sucks as usual, except for the app situation, which sucks even more now that x64 is the flavor of the month and there are so few apps for Solaris x64.