On 16/04/2012, at 20:12, Russell Coker <russell@coker.com.au> wrote:
I've got a few of my systems (including some with data that is important to me) using BTRFS now. It's been going well and one of my systems has had BTRFS for /home for ages (maybe a year) with no problems in recent times (some past problems when running out of space).
One of my clients needs to reliably store terabytes of data which is mostly comprised of data files in the 10MB - 15MB size range. The data files will almost never be re-written and I anticiapte that the main bottleneck will be the latency of NFS and other network file sharing protocols. I would hope that saturating a GigE network when sending 10MB data files from SATA disks via NFS, AFS, or SMB wouldn't be a technical challenge.
It seems that BTRFS is the way of the future. But it's still rather new and the lack of RAID-5 is a serious issue when you need to store 10TB with today's technology (that would be 8*3TB disks for RAID-10 vs 5*3TB disks for RAID-5).
ZFS seems to be a lot more complex than BTRFS. While having more features is a good thing (BTRFS seems to be missing some sysadmin friendly features) complexity means more testing and more potential for making mistakes.
Of course it might turn out that RAID-5 is the killer issue. Servers start becoming a lot more expensive if you want more than 8 disks and even 6 disks is a significant price point. An 8 disk RAID-5 gives something like 21TB usable space vs 12TB on a RAID-10 and a 6 disk RAID-5 gives about 15TB vs 9TB on a RAID-10.
Anything else I should consider?
Not that I've got anything to add re ZFS vs BTRFS having no specialist knowledge either way, but in other posts haven't you advocated for RAID-6 over RAID-5? Or is this something mandated on the client side?