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

[Ma Begaj]

2008/10/23 Yeechang Lee <ylee at pobox.com>:
> Mache Creeger <mache at creeger.com> says:
>> Lally Singh recommends a ZDNet piece predicting
>> the imminent demise of RAID 5
>
> Depends on the circumstances, of course. I've had reason to be glad my
> 16-disk MythTV-recording array is RAID 6, not 5. My three-, four-, and
> currently out-of-commission eight-disk arrays are RAID 5, and in my
> view the risks are acceptable.
>
> If and when I ever spring for a new recording array based on whatever
> is the highest-capacity drive at the time, the number of drives will
> determine how it's configured. If 16, I'd likely again go RAID 6. If
> 20 (Or even more?), I'd likely multiple RAID 5 or 6 arrays.
>
>> This reader adds, "Apparently, RAID 6 isn't far behind. I'll keep
>> the ZFS plug short. Go ZFS. There, that was it."
>
> I'd love to use ZFS, but there's no sign it's going to be incorporated
> into the Linux kernel anytime soon. I'd have to build and maintain an
> OpenSolaris box just for ZFS, and although I'm open to it given ZFS's
> benefits it'd mean I wouldn't be able to run a slave backend on it.

Last time I read about ZFS I was not able to find any special features
which could not be done with RAID and LVM. Snapshots are pretty nice
feature, but FreeBSD had it years ago and I never used it much because
it was no solution for backup. And snapshots made with ZFS can also be
made with "cp" and hard linking.

As I see this, only really nice feature of ZFS is to have everything
under one roof without having to use external tools like mdadm and/or
lvm. And I would still rather use mdadm/lvm with "my" filesystem
instead of ZFS, because they are longer (tested) on the market.