[mythtv-users] Why RAID 5 stops working in 2009

[John Drescher]

> I will, but I'm still a few months out most likely. I don't think you would
> be able to add disks to the individual raidz, you would create a new one in
> the pool. So you will have a second parity disk, but that's a good thing
> with a 20 disk RAID. I'd probably put 5 disks in each raidz and put the 4
> raidz devices into a single pool. Then create the filesystems on top of all
> that. Then you can lose any 1 disk in each 5-disk raidz before losing data.
>
> This is all based on reading the docs, I haven't tried it myself on real
> hardware yet. If you have zfs-fuse installed, you can use files as the block
> devices in ZFS (loopback filesystem images). So you can do this testing
> yourself on your intended platform. I might try it in VMWare myself now that
> I think about it. :)
>

Has performance drastically improved in the last year with the
zfs-fuse module? I tried it back then and got hdparm reads and dd
writes of less than 20MB/s on an array that does 250 MB/s+ writes.

John