John McKown said: > Isn't that the 128-bit filesystem? <shakes head> I don't even have > enough DASD to create a real 64-bit filesystem. 128-bit is just plain > overkill, for me. > > Does ZFS have any other enhancements that I'm not aware of?
128 bits is overkill for everyone! That's pretty much the idea: if we're going to have the disruptive event of a new file system, we want it to last a very long time (file systems persist 20 years and more, so best to design for the future), and not for the threshold of current disk capabilities. Jeff Bonwick (ZFS lead, also inventor of the "slab allocator") blogged on the quantum physics consequence: "fully populating a 128-bit storage pool would, literally, require more energy than boiling the oceans": http://blogs.sun.com/bonwick/entry/128_bit_storage_are_you Pragmatically, this means that we don't have to change file systems or mess about with volume managers when a production file system reaches 40TB. In fact, with ZFS you don't need volume managers at all. To answer John's question, ZFS has other functional benefits, which I'll list briefly (anyone wanting further discussion, please contact me off-list; I don't want to propagate OT discussions any more than necessary): - remove architectural constraints on capacity (the 128 bit aspect) - data integrity to avoid silent data corruption - on-disk format is always consistent; fsck doesn't exist - copy on write (COW) semantics at transaction boundary - every block (both data and metadata) checksummed. Protects against the many failure modes (media failure, phantom write, bit rot, driver failures, misdirected read or writes, etc.) - auto-repair of bad side of mirrored data; disk scrubbing - Easier administration; pooled storage without need for volume manager Easy to set quotas, disk reservations, mirrors, compressions, clones, snapshots, migration, fs growth - Endian-neutral on-disk data There is interest in porting ZFS to other systems (Apple, BSD): http://www.opensolaris.org/os/community/zfs/porting/ Maybe there will be more. I really don't know - the right thing to do is join the open source community. If Solaris goes GPL (also recently discussed. No, I have no idea how likely that is!) then maybe that removes the objection to a Linux port. There are also other attractive features in Solaris (some of which, like DTrace, are also involved in ports), so there are other factors motivating ports. To Alan's mention of Solaris on x86, I'll comment that of the 6 million+ registered downloads of Solaris, about 2/3 have been on x86 rather than SPARC. The majority of those are not on Sun's x86 systems. There's also very substantial ISV uptake now for Solaris running on Intel and AMD. So, while Sun in the past (unfortunately) did not encourage Solaris on x86 in the past, there is now a substantial and growing following. VMware, Xen, and Parallels (I saw Solaris under Parallels on Mac laptops) adds more interesting data points. Whether that would apply equally to the POWER port to the System z port will be interesting to see. regards to all, Jeff ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
