Hi, On 7/21/21 9:40 AM, mabi wrote:
Hello, I need to relocate an Octopus (15.2.13) ceph cluster of 8 nodes to another internal network. This means that the IP address of each nodes as well as the domain name will change. The hostname itself will stay the same. What would be the best steps in order to achieive that from the ceph side? I did not find any relevant documentation to such a procedure. This cluster is installed with cephadm and runs on Ubuntu 20.04.
You need to ensure that TCP traffic is routeable between the networks for the migration. OSD only hosts are trivial, an OSD updates its IP information in the OSD map on boot. This should also be the case for MDS, MGR, RGW, mirror agents and other services.
MONs are a different beast. You cannot change the IP address of an existing mon (or with way too much effort). I would thus recommend to remove one mon, migrate the machine to the new network, and re-add the mon afterwards. Repeat with the other mons etc.
You will also need to adapt ceph.conf on each host (servers and clients) to the new IP addresses or update the DNS configuration if you use SRV entries. Running instances will be updated automatically (notification of changes in the mon map), but newly started clients/services might fail if they try to use the old IP addresses. This is why ceph.conf is create by puppet in our setup......
One client with special needs is openstack cinder. The database entries contain the mon list for volumes, and I'm not aware of a good method to update them except manipulating the database. If you also use ceph for nova (root disks / ephemerals), the problem might also be present there. libvirt also has a list of mon hosts in the domain description for each instance that is using ceph based block storage. I'm not 100% sure whether this is updated e.g. during a live migration. Or what will happen if you shutdown an instance and restart it after the migration (domain xml file will not be recreated and might contain stale information...).
Regards, Burkhard _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
