On Sun, 31 Aug 2008, Ross wrote: > You could split this into two raid-z2 sets if you wanted, that would > have a bit better performance, but if you can cope with the speed of > a single pool for now I'd be tempted to start with that. It's > likely that by Christmas you'll be able to buy flash devices to use > as read or write cache with ZFS, at which point the speed of the > disks becomes academic for many cases.
We have not heard how this log server is going to receive the log data. Receiving the logs via BSD logging protocol is much different than receiving the logs via a NFS mount. If the logs are received via BSD logging protocol then the writes will be asynchronous and there is no need at all for a NV write cache. If the logs are received via NFS, then the writes are synchronous so there may be need for a NV write cache in order to maintain adequate performance. Luckily the StorageTek 2540 provides a reasonable NV write cache already. Without performing any actual testing to prove it, I would assume that two raidz2 sets will offer almost 2X the transactional performance of one bit raidz2 set, which may be important for a logging server which is receiving simultaneous input from many places. For reliability, I definitely recommend something like the BSD logging protocol if it can be used since it is more likely to capture all of the logs if there is a problem. Bob ====================================== Bob Friesenhahn [EMAIL PROTECTED], http://www.simplesystems.org/users/bfriesen/ GraphicsMagick Maintainer, http://www.GraphicsMagick.org/ _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
