On 16.02.2013 13:48, Roy Sigurd Karlsbakk wrote: >> On 14.02.2013 18:48, Jeff Johnson wrote: >>> Stable enough where it is being used at Lawrence Livermore Nat'l >>> Labs on >>> a 55PB Lustre resource. >>> >>> I've been using it on a pre-release Lustre 2.4 and I have not had >>> any >>> issues. >> >> ZFS completely fragments if you've got massive parallel write IO - >> especially with Solaris 11. You'll get only 2..3 MiB/s after some time >> as everything is stored completely random then. So if you don't really >> need these snapshots you shouldn't use ZFS. NILFS is also good for >> snapshots. > > This won't be massive parallel I/O, just a fileserver with a limited amount of users. Also, can you document this claim? Of cause, we had ZFS in production in our IaaS public cloud. In such a cloud nearly everything is random. Customers create and delete their storage from time to time and some of them do a lot of small writes. It fills up quite fast. We even had no snapshots and we already had the ZIL dedicated on enterprise SSDs. http://thomas.gouverneur.name/2011/06/20110609zfs-fragmentation-issue-examining-the-zil/ http://www.racktopsystems.com/dedicated-zfs-intent-log-aka-slogzil-and-data-fragmentation/ http://www.eall.com.br/blog/?p=2481 http://www.techforce.com.br/news/layout/set/print/linux_blog/zfs_part_4_sustained_random_small_files_sync_write_iops ZFS as block device with COMSTAR exports is really crap. You've got mostly synchronous (and small database) IO. This is why we switched to a Linux storage with LVM (without thin stuff). The customers run their file systems in their VMs anyway. Cheers, Sebastian -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
