[Gluster-users] Production cluster planning

[Gandalf Corvotempesta]

2016-10-26 23:07 GMT+02:00 Joe Julian <joe at julianfamily.org>:
> And yes, they can fail, but 20TB is small enough to heal pretty quickly.

20TB small enough to build quickly? On which network? Gluster doesn't
have a dedicated cluster network, if the cluster is being hevily
accessed, the healing will slow down everything else (or everything
else will slow down the healing)

Anyway, you can heal quickly, but I still prefere to have data safe on
each node. If you start with 3 server at once, probably each disk is
coming from the same batch, thus a massive disks failure is easy to
get.
If you loose only 2 disks, one for each server, from the same replica
group, you are game over. With RAID6, you have to loose 5 disks from
the same replica group.

In my environment, I can create 4 RAID-0 on each server (3 disks on
each RAID0), or 2 RAID-6 with 6 disks each, or 1 RAID-6 with 12 disks
or 1 RAID-7 with 12 disks (RAID-7 with less than 12 disks is
non-sense)
I don't know which one is better.