[Gluster-users] to RAID or not?

[Matt Robinson]

If you don't trust the hardware raid, then steer clear of raid-6 as mdadm raid 6 is stupidly slow.
I don't completely trust hardware raid either, but rebuild times should be under a day and in order to lose a raid-6 array you have to lose 3 disks.
My own systems are hardware raid-6.
If you're not terribly worried about maximising usable storage, then mdadm raid-10 is your friend.


> On 4 Jul 2016, at 18:15:26, Gandalf Corvotempesta <gandalf.corvotempesta at gmail.com> wrote:
> 
> 2016-07-04 17:01 GMT+02:00 Matt Robinson <m.robinson at sheffield.ac.uk>:
>> Hi Gandalf,
>> 
>> Are you using hardware raid or mdadm?
>> On high quality hardware raid, a 12 disk raid-6 is pretty solid.  With mdadm any raid6 (especially with 12 disks) will be rubbish.
> 
> I can use both.
> I don't like very much hardware raid, even high quality. Recently i'm
> having too many issue with hardware raid (like multiple disks kicked
> out with no apparent reasons and virtual-disk failed with data loss)
> 
> A RAID-6 with 12x2TB SATA disks would take days to rebuild, in the
> meanwhile, multiple disks could fail resulting in data loss.
> Yes, gluster is able to recover from this, but I prefere to avoid have
> to resync 24TB of data via networks.
> 
> What about a software RAID-1 ? 6 raid for each gluster nodes and 6
> disks wasted but SATA disks are cheaper.