Il 09 ago 2016 10:06 AM, "Ashish Pandey" <aspandey@xxxxxxxxxx> ha scritto:
> If your main concern is data redundancy, I would suggest you to go for erasure coded volume provided by gluster.
Anyway EC volumes has a lower redundancy level than standard replicated volumes.
Let's assume a 9 nodes cluster with 12 disks on each node, redundancy set to 2
You have 9*12 = 108 disks/bricks
with redundancy 2 you can loose up to 2 bricks/disks at the same time before loosing data. Using cheap sata disks (gluster is made to run on commodity hardware) loosing 3 disks over 108 in a very short time could happen frequently and this frequency grow as cluster grows
With a standard replicated volume, with replica 3, you can loose up to 3 servers (not bricks) because each brick in a replica set must be on a different server.
I think EC is something like raid6 (with more "parity") and standard replication is like raid10 but with 3 disks for each mirror.
Raid10 is safer as you can loose as many disks as you want, if in different replica set, while raid 6 can loose up to 2 disks in the whole cluster
Higher the number of disks, higher the probability of data loss with raid6/EC
Am i missed something?
_______________________________________________ Gluster-users mailing list Gluster-users@xxxxxxxxxxx http://www.gluster.org/mailman/listinfo/gluster-users
