Hi Paul
Thanks for your reply! They indeed are except the
crush-failure-domain=host vs crush-failure-domain=rack. The latter has
the preference since I've spread my OSD's on 2 seperate DC's.
As far as I know, modifying the crush rule on an existing / running pool
isn't possible (at least not on mimic not sure about nautilus). I quote
from the following Red Hat documentation found here:
https://access.redhat.com/documentation/en-us/red_hat_ceph_storage/1.2.3/ht…
and it goes: "Choosing the right profile is important because you cannot
change the profile after you create the pool. To modify a profile, you
must create a new pool with a different profile and migrate the objects
from the old pool to the new pool."
Also, let's assume it was possible, how would I modify my crush rules so
I could afford losing one DC without data loss?
On 7/30/19 11:24 PM, Paul Emmerich wrote:
On Sat, Jul 27, 2019 at 11:51 PM Valentin Bajrami
<valentin.bajrami(a)target-holding.nl> wrote:
Hello There,
Recently, I've been reading about how to migrate an existing EC pool which has the
following profile:
crush-device-class=
crush-failure-domain=host
crush-root=default
jerasure-per-chunk-alignment=false
k=2
m=2
plugin=jerasure
technique=reed_sol_van
w=8
To a new EC pool with the following profile:
crush-device-class=
crush-failure-domain=rack
crush-root=default
jerasure-per-chunk-alignment=false
k=2
m=2
plugin=jerasure
technique=reed_sol_van
w=8
These ec profiles are effectively identical. You can just change the
CRUSH rule of the pool.
--
Met vriendelijke groeten,
Valentin Bajrami
Target Holding