Comment on Longhorn overkill for RAID ?
Burn1ngBull3t@lemmy.world 9 months agoYou are completely right.
However in my mind (might be wrong here) if I use another node, i wouldn’t use the RAID array completely.
While setup up i thought that its either:
- NAS storageClass attached to the RAID array, no longhorn
- with longhorn when there is no RAID, but replication at 3
In either case, the availability of my data would be quite the same right ?
(Then there is options to backup my PV to s3 with longhorn and all that i would have to setup again though )
Thanks for your answer !
Starbuck@lemmy.world 9 months ago
You’re on the right track here. Longhorn kind of makes RAID irrelevant, but only for data stored in Longhorn. So anything on the host disk and not a PV is at risk. I tend to use MicroOS and k3s, so I’m okay with the risk, but it’s worth considering.
For replicas, I wouldn’t jump straight to 3 and ignore 2. A lot of distributed storage systems use 3 so that they can resolve the “split brain” problem. Basically, if half the nodes can’t talk to each other, the side with quorum (2 of 3) knows that it can keep going while the side with 1 of 3 knows to stop accepting writes it can’t replicate. But Longhorn already does this in a Kubernetes native way. So it can get away with replica 2 because only one of the replicas will get the lease from the kube-api.