On Wed, 7 Apr 2010, Jason S wrote:
To keep the pool size at 12TB i would have to give up my extra parity drive going to this 2 array setup and it is concerning as i have no room for hot spares in this system. So in my mind i am left with only one other choice and this is going to 2XRaidZ2 pools and loosing an additional 2 TB so i am left with a 10TB ZFS pool.
I would go with a single pool with two raidz2 vdevs, even if you don't get the maximum possible space. Raidz is best avoided when using 1GB SATA disk drives because of the relatively high probability of data loss during a resilver and the long resilver times. I would trade the hot spare for the improved security of raidz2. The hot spare is more helpful for mirrored setups or raidz1, where the data reliability is more sensitive to how long it takes to recover a lost drive. Just buy a spare drive so that you can replace a failed drive expediently.
So my big question is given that i am working with 4mb - 50gb files is going with 14 spindles going incur a huge performance hit? I was hoping to be able to saturate a single GigE link with this setup, but i am concerned the single large array wont let me achieve this.
It is not difficult to saturate a gigabit link. It can be easily accomplished with just a couple of drives. The main factor is if zfs's prefetch is aggressive enough. Each raidz2 vdev will offer the useful IOPS of a single disk drive so from an IOPS standpoint, the pool would behave like two drives.
Bob -- Bob Friesenhahn bfrie...@simple.dallas.tx.us, 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
