On Dec 6, 2007 1:13 AM, Bakul Shah <[EMAIL PROTECTED]> wrote: > Note that I don't wish to argue for/against zfs/billtodd but > the comment above about "no *real* opensource software > alternative zfs automating checksumming and simple > snapshotting" caught my eye. > > There is an open source alternative for archiving that works > quite well. venti has been available for a few years now. > It runs on *BSD, linux, macOS & plan9 (its native os). It > uses strong crypto checksums, stored separately from the data > (stored in the pointer blocks) so you get a similar guarantee > against silent data corruption as ZFS.
Last time I looked into Venti, it used content hashing to locate storage blocks. Which was really cool, because (as you say) it magically consolidates blocks with the same checksum together. The 45 byte score is the checksum of the top of the tree, isn't that right? Good to hear it's still alive and been revamped somewhat. ZFS snapshots and clones save a lot of space, but the 'content-hash == address' trick means you could potentially save much more. Though I'm still not sure how well it scales up - Bigger working set means you need longer (more expensive) hashes to avoid a collision, and even then its not guaranteed. When i last looked they were still using SHA-160 and I ran away screaming at that point :) > Google for "venti sean dorward". If interested, go to > http://swtch.com/plan9port/ and pick up plan9port (a > collection of programs from plan9, not just venti). See > http://swtch.com/plan9port/man/man8/index.html for how to use > venti. -- Rasputnik :: Jack of All Trades - Master of Nuns http://number9.hellooperator.net/ _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
