How can I change the num-replicas on ceph pool online? Need to go from 6/3 to 3/2

[Batpenguin]

How can I change the num-replicas on ceph pool online? I need to change the pool from 6 to 3 and the minimum from 3 to 2. I have VMs running in the ceph pool and don't want to loose them. I saw this post https://forum.proxmox.com/threads/change-num-replicas-on-ceph-rool-online.25904/ but want to make sure by going smaller I won't loose my data. Each server has 2 6TB drives that are in the ceph storage. only a fraction of the storage has been used, less than 6 TB.
Thanks in Advance!!

 

[HisMastersVoice]

Found this: https://forum.proxmox.com/threads/change-num-replicas-on-ceph-rool-online.25904/
Cross-read ceph documentation just to be sure.

 

[Batpenguin]

Found this: https://forum.proxmox.com/threads/change-num-replicas-on-ceph-rool-online.25904/
Cross-read ceph documentation just to be sure.

I saw that post, they were increasing the size of the replicas and I want to decrease. Didn't know if that would work the same.

 

[NoahD]

You can always increase the numbers but not decrease so only way to fix this is create a new storage pool and migrate the VMs and containers to it. Then destroy the old pool to reclaim the disk space. As always make a backup of your VMs and containers on a separate disk first before doing anything.

 

[spirit]

You can always increase the numbers but not decrease so only way to fix this is create a new storage pool and migrate the VMs and containers to it. Then destroy the old pool to reclaim the disk space. As always make a backup of your VMs and containers on a separate disk first before doing anything.

That's not true, you are talking about PG. (and with nautilus you can decrease them too).


size && min_size can be change online.

ceph osd pool set mypool size 3
ceph osd pool set mypool min_size 2

 

[NoahD]

That's not true, you are talking about PG. (and with nautilus you can decrease them too).


size && min_size can be change online.

ceph osd pool set mypool size 3
ceph osd pool set mypool min_size 2

Ok, I stand corrected. Still I would make backups first.

 

[Batpenguin]

That's not true, you are talking about PG. (and with nautilus you can decrease them too).


size && min_size can be change online.

ceph osd pool set mypool size 3
ceph osd pool set mypool min_size 2

Thanks for everyone's replies. Spirit, would I need to do that on all nodes or just one?

 

[spirit]

Thanks for everyone's replies. Spirit, would I need to do that on all nodes or just one?

you only need to do it once, on your cluster. (so, once on any node)

 

[Batpenguin]

you only need to do it once, on your cluster. (so, once on any node)

Thanks again. If you ever find yourself in St. Louis, MO in the USA look me up I will take you to some of the best American BBQ joints in the world and some nice local breweries all on me. I really mean it!! I work in IT in a full time job and I also do a lot of side work. Been working 80 hours plus a week almost all of this Month. So I made this mistake because I was tired. I was doing side work for a friend of a friend at his business. This was stressing me out beyond belief. I can't say thank you enough!!!