Le 08/11/2023 à 19:29:19+0100, David C. a écrit Hi David.
What would be the number of replicas (in total and on each row) and their distribution on the tree ?
Well “inside” a row that would be 3 in replica mode. Between row...well two ;-) Beside to understanding how to write a rule a little more complex than the example in the official documentation, they are another purpose and it's to try to have a protocole for changing the hardware. For example if «row primary» are only with old bare metal server, and I have some new server I put inside the ceph and want to copy everything from the “row primary” to “row secondary”. Regards
Le mer. 8 nov. 2023 à 18:45, Albert Shih <Albert.Shih@obspm.fr> a écrit :
Hi everyone,
I'm totally newbie with ceph, so sorry if I'm asking some stupid question.
I'm trying to understand how the crush map & rule work, my goal is to have two groups of 3 servers, so I'm using “row” bucket
ID CLASS WEIGHT TYPE NAME STATUS REWEIGHT PRI-AFF -1 59.38367 root default -15 59.38367 zone City -17 29.69183 row primary -3 9.89728 host server1 0 ssd 3.49309 osd.0 up 1.00000 1.00000 1 ssd 1.74660 osd.1 up 1.00000 1.00000 2 ssd 1.74660 osd.2 up 1.00000 1.00000 3 ssd 2.91100 osd.3 up 1.00000 1.00000 -5 9.89728 host server2 4 ssd 1.74660 osd.4 up 1.00000 1.00000 5 ssd 1.74660 osd.5 up 1.00000 1.00000 6 ssd 2.91100 osd.6 up 1.00000 1.00000 7 ssd 3.49309 osd.7 up 1.00000 1.00000 -7 9.89728 host server3 8 ssd 3.49309 osd.8 up 1.00000 1.00000 9 ssd 1.74660 osd.9 up 1.00000 1.00000 10 ssd 2.91100 osd.10 up 1.00000 1.00000 11 ssd 1.74660 osd.11 up 1.00000 1.00000 -19 29.69183 row secondary -9 9.89728 host server4 12 ssd 1.74660 osd.12 up 1.00000 1.00000 13 ssd 1.74660 osd.13 up 1.00000 1.00000 14 ssd 3.49309 osd.14 up 1.00000 1.00000 15 ssd 2.91100 osd.15 up 1.00000 1.00000 -11 9.89728 host server5 16 ssd 1.74660 osd.16 up 1.00000 1.00000 17 ssd 1.74660 osd.17 up 1.00000 1.00000 18 ssd 3.49309 osd.18 up 1.00000 1.00000 19 ssd 2.91100 osd.19 up 1.00000 1.00000 -13 9.89728 host server6 20 ssd 1.74660 osd.20 up 1.00000 1.00000 21 ssd 1.74660 osd.21 up 1.00000 1.00000 22 ssd 2.91100 osd.22 up 1.00000 1.00000
and I want to create a some rules, first I like to have
a rule «replica» (over host) inside the «row» primary a rule «erasure» (over host) inside the «row» primary
but also two crush rule between primary/secondary, meaning I like to have a replica (with only 1 copy of course) of pool from “row” primary to secondary.
How can I achieve that ?
Regards
-- Albert SHIH 🦫 🐸 mer. 08 nov. 2023 18:37:54 CET _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-leave@ceph.io
-- Albert SHIH 🦫 🐸 Observatoire de Paris France Heure locale/Local time: jeu. 09 nov. 2023 08:39:41 CET