Re: [zfs-discuss] redundancy in non-redundant stripes

2008-12-05 Thread Richard Elling
Mike Brancato wrote: > With ZFS, we can enable copies=[1,2,3] to configure how many copies of data > there are. With copies of 2 or more, in theory, an entire disk can have read > errors, and the zfs volume still works. No, this is not a completely true statement. > The unfortunate part here

Re: [zfs-discuss] redundancy in non-redundant stripes

2008-12-05 Thread Mike Brancato
In theory, with 2 80GB drives, you would always have a copy somewhere else. But a single drive, no. I guess I'm thinking in the optimal situation. With multiple drives, copies are spread through the vdevs. I guess it would work better if we could define that if copies=2 or more, that at leas

Re: [zfs-discuss] redundancy in non-redundant stripes

2008-12-05 Thread Bob Friesenhahn
On Fri, 5 Dec 2008, Mike Brancato wrote: > With ZFS, we can enable copies=[1,2,3] to configure how many copies > of data there are. With copies of 2 or more, in theory, an entire > disk can have read errors, and the zfs volume still works. So you are saying that if we use copies of 2 or more t

[zfs-discuss] redundancy in non-redundant stripes

2008-12-05 Thread Mike Brancato
With ZFS, we can enable copies=[1,2,3] to configure how many copies of data there are. With copies of 2 or more, in theory, an entire disk can have read errors, and the zfs volume still works. The unfortunate part here is that the redundancy lies in the volume, not the pool vdev like with ra