[ceph-users] Re: Crush Map and CEPH meta data locations

2020-08-04 Thread Gregor Krmelj
Ah, really good question :) I believe it is stored locally on the monitor host. Saving the cluster map into RADOS would result in a chicken or egg problem. This is supported by the following two sections in the docs: 1. https://docs.ceph.com/docs/master/rados/configuration/mon-config-ref/#bac

[ceph-users] Re: Crush Map and CEPH meta data locations

2020-08-04 Thread Edward kalk
Thank you Gregor for the reply. I have read that page. It does say what a Crush map is and how it’s used by monitors and OSDs, but does not say how or where the map is stored in the system. Is it replicated on all OSD, vis a distributed hidden pool? Is it stored on the local linux disk of the ho

[ceph-users] Re: Crush Map and CEPH meta data locations

2020-08-03 Thread Gregor Krmelj
The CRUSH map makes up the so called "Cluster Map", for which the Ceph Monitors maintain a master copy. This is precisely why you have multiple monitors - for high availability in case a monitor goes down. This is all explained quite well in the architecture documentation: https://docs.ceph.com