The failure domain is baked into the crush rule that is
created for a pool. To allow for an updated failure domain
on the pool, create a new crush rule specific for that
failure domain and update the pool with the new rule.
Signed-off-by: Travis Nielsen <tnielsen@redhat.com>
Creates hybrid crush rule for choosing Primary OSD for
high performing SSD devices and remaining OSD for low performance HDD devices.
Signed-off-by: Santosh Pillai <sapillai@redhat.com>
When 'pool.Replicated.ReplicasPerFailureDomain' is non zero, the code
goes via route of adding explicit crush-rule from template, but ignores
the 'pool.DeviceClass' if it is set. Added option to template to have
(optional) 'class hdd|ssd'
Signed-off-by: Shachar Sharon <ssharon@redhat.com>
In clusters where only two datacenters (or similar failure domains)
are available, a different mon and osd approach is needed to deal
with the network partitions or some other reason for one of the failure
domains going down. The Ceph stretched cluster makes the mons aware
of the failure domains by configuring one as the arbiter in a third
zone, while keeping two replicas of the data in each of the data
zoens.
Signed-off-by: Travis Nielsen <tnielsen@redhat.com>
The pool spec has now a new property called "replicasPerFailureDomain"
which essentially represents the number of replicas to store in each
failure domain.
Assuming the failure domain is a datacenter (if the cluster is
stretched) then you will have 2 replicas per datacenter where each
replica ends up on a different host. This gives you a total of 4
replicas and for this, the "size" must be set to 4.
Closes: https://github.com/rook/rook/issues/5591
Signed-off-by: Sébastien Han <seb@redhat.com>
Travis Nielsen
Santosh Pillai
Shachar Sharon
Sébastien Han