Re: moving small production cluster to different datacenter
On 1/28/20 6:58 PM, Anthony D'Atri wrote:
I did this ones. This cluster was running IPv6-only (still is) and thus I had the flexibility of new IPs.
Dumb question — how was IPv6 a factor in that flexibility? Was it just that you had unused addresses within an existing block?
There are no dumb questions :-) Usually Ceph is put into RFC1918 IPv4 space (10.x, 172.X) and those are usually more difficult to route in networks. IPv6 address space is globally routed in most networks thus making this easier. As long as the hosts can talk IP(4/6) with each other you can perform such a migration. Wido
Did you end up having all new IPs for your MONs? I've wondered how should a large KVM deployment be handled when the instance-metadata has a hard-coded list of MON IPs for the cluster? how are they changed en-masse with running VMs? or do these moves always result in at least one MON with an original IP? e.g. https://bugzilla.redhat.com/show_bug.cgi?id=1314099
On 1/31/20 12:09 AM, Nigel Williams wrote:
Did you end up having all new IPs for your MONs? I've wondered how should a large KVM deployment be handled when the instance-metadata has a hard-coded list of MON IPs for the cluster? how are they changed en-masse with running VMs? or do these moves always result in at least one MON with an original IP?
Any running VM will get the updated monmap and will handle that properly. However, if you stop and start the VM with the same XML definition it will not start anymore. Therefor I've always used Round Robin DNS pointing to the Monitors. Wido
e.g. https://bugzilla.redhat.com/show_bug.cgi?id=1314099 _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-leave@ceph.io
Hi, On 1/31/20 12:09 AM, Nigel Williams wrote:
Did you end up having all new IPs for your MONs? I've wondered how should a large KVM deployment be handled when the instance-metadata has a hard-coded list of MON IPs for the cluster? how are they changed en-masse with running VMs? or do these moves always result in at least one MON with an original IP?
CEPH client are also able to lookup the mon address via DNS SRV entries (see https://docs.ceph.com/docs/mimic/rados/configuration/mon-lookup-dns/). Might be worth testing this with libvirt. Regards, Burkhard -- Dr. rer. nat. Burkhard Linke Bioinformatics and Systems Biology Justus-Liebig-University Giessen 35392 Giessen, Germany Phone: (+49) (0)641 9935810
participants (3)
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Burkhard Linke
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Nigel Williams
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Wido den Hollander