zfs-discuss@opensolaris.org
[Top] [All Lists]

Re: [zfs-discuss] Size discrepancy (beyond expected amount?)

Subject: Re: [zfs-discuss] Size discrepancy beyond expected amount?
From: Bob Friesenhahn
Date: Fri, 20 Mar 2009 09:57:55 -0500 CDT
On Thu, 19 Mar 2009, Harry Putnam wrote:

So raidz1 would probably be adequate for me... I wouldn't be putting
it to the test like a commercial operation might.

Yes, but it is pointless to use it with three disks since a mirror provides the same space using only two disks and is therefore 1/3 less likely to encounter a disk or media failure.

You mentioned admistration was a bigger problem with raidz1, can you
be more specific there?... I have really know idea what to expect in
that regard with either technique.

Mirrors are quite simple. Simple is good. Mirrors resilver faster if you have to replace a drive or a drive is accidentally unplugged for a while.

With five disks, raidz1 becomes useful.

The three 500gb I have now are all one brand and model number and IDE ata.
If I were to expand to 5, those 2 would need to be sata or else I'd
also need to add a PCI IDE controller.

With that in mind would it be problematic to make up the 5 by adding 2
sata 500gb to the mix?

Adding a few more drives so that you have at least five drives would get you to the point where raidz1 is useful and you will have more space available. At the moment there is no way to expand the size of a raidz vdev other than by replacing all of the disks with larger disks. You can't add additional drives to a vdev. So you need to install the drives from the very beginning.

Bob
--
Bob Friesenhahn
bfriesen@xxxxxxxxxxxxxxxxxxx, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/
_______________________________________________
zfs-discuss mailing list
zfs-discuss@xxxxxxxxxxxxxxx
http://mail.opensolaris.org/mailman/listinfo/zfs-discuss

<Prev in Thread] Current Thread [Next in Thread>