[Gluster-users] Settings for VM hosting

[lemonnierk at ulrar.net]

On Thu, Apr 18, 2019 at 03:13:25PM +0200, Martin Toth wrote:
> Hi,
> 
> I am curious about your setup and settings also. I have exactly same setup and use case.
> 
> - why do you use sharding on replica3? Do you have various size of bricks(disks) pre node?
>

Back in the 3.7 era there was a bug locking the files during heal. So
without sharding the whole disk was locked for ~30 minutes (depending on
the disk's size of course), it was briningh the whole service down
during heals.

We started using shards then because it locks only the shard being
healed instead of the whole file, I believe the bug has been fixed since
but we've kept it just in case.

As a bonus combined to the heal algo full (just re-transmit the shard
instead of trying to figure out what's changed) it's much, much faster
heal times with very little cpu usage, so really there's no reason not
to imho, sharding is great.
Might be different if you have big dedicated servers for gluster and
nothing else to do with your cpu, I don't know, but for us sharding is a
big gain during heals, which unfortunatly is very common on OVH's shaky
vRacks :(