Yes, of course this works. For some reason I recall having trouble when I tried this on my first ceph install. But I think in that case I didn't change the crush tree, but instead I had changed the device classes without changing the crush tree. In any case, the re-crush worked fine. --Mike On 11/10/20 4:20 PM, DHilsbos@performair.com wrote:

Michael;

I run a Nautilus cluster, but all I had to do was change the rule associated with the pool, and ceph moved the data.

Thank you,

Dominic L. Hilsbos, MBA Director - Information Technology Perform Air International Inc. DHilsbos@PerformAir.com www.PerformAir.com

-----Original Message----- From: Michael Thomas [mailto:wart@caltech.edu] Sent: Tuesday, November 10, 2020 1:32 PM To: ceph-users@ceph.io Subject: [ceph-users] safest way to re-crush a pool

I'm setting up a radosgw for my ceph Octopus cluster. As soon as I started the radosgw service, I notice that it created a handful of new pools. These pools were assigned the 'replicated_data' crush rule automatically.

I have a mixed hdd/ssd/nvme cluster, and this 'replicated_data' crush rule spans all device types. I would like radosgw to use a replicated SSD pool and avoid the HDDs. What is the recommended way to change the crush device class for these pools without risking the loss of any data in the pools? I will note that I have not yet written any user data to the pools. Everything in them was added by the radosgw process automatically.

--Mike _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-leave@ceph.io