On Tue, 2009-06-02 at 16:36 +1000, Adam Goryachev wrote: > -----BEGIN PGP SIGNED MESSAGE----- > > With a modern filesystem capable of multiple copies of each file this > > can be overcome. ZFS can handle multiple drive failures by selecting the > > number of redundant copies of each file to store on different physical > > volumes. Simply put, a ZFS RAIDZ with 4 drives can be set to have 3 > > copies which would allow 2 drives to fail. This is somewhat better than > > RAID1 and RAID5 both because more storage is available yet still allows > > up to 2 drives to fail before leaving a rebuild hole where the storage > > is vulnerable to a single drive failure during a rebuild or resilver. > > So, using 4 x 100G drives provides 133G usable storage... we can lose > any two drives without any data loss. However, from my calculations > (which might be wrong), RAID6 would be more efficient. On a 4 drive 100G > system you get 200G available storage, and can lose any two drives > without data loss.
So isn't this the same as RAID10 w/ 4 drives, 200GB and can lose 2 drives (as long as they aren't on the same mirror) and no risk of corrupted parity blocks? ------------------------------------------------------------------------------ OpenSolaris 2009.06 is a cutting edge operating system for enterprises looking to deploy the next generation of Solaris that includes the latest innovations from Sun and the OpenSource community. Download a copy and enjoy capabilities such as Networking, Storage and Virtualization. Go to: http://p.sf.net/sfu/opensolaris-get _______________________________________________ BackupPC-users mailing list BackupPC-users@lists.sourceforge.net List: https://lists.sourceforge.net/lists/listinfo/backuppc-users Wiki: http://backuppc.wiki.sourceforge.net Project: http://backuppc.sourceforge.net/
