Hello, I'm about to add another storage node to small firefly cluster here and refurbish 2 existing nodes (more RAM, different OSD disks). Insert rant about not going to start using ceph-deploy as I would have to set the cluster to no-in since "prepare" also activates things due to the udev magic... This cluster is quite at the limits of its IOPS capacity (the HW was requested ages ago, but the mills here grind slowly and not particular fine either), so the plan is to: a) phase in the new node (lets call it C), one OSD at a time (in the dead of night) b) empty out old node A (weight 0), one OSD at a time. When done, refurbish and bring it back in, like above. c) repeat with 2nd old node B. Looking at this it's obvious where the big optimization in this procedure would be, having the ability to "freeze" the OSDs on node B. That is making them ineligible for any new PGs while preserving their current status. So that data moves from A to C (which is significantly faster than A or B) and then back to A when it is refurbished, avoiding any heavy lifting by B. Does that sound like something other people might find useful as well and is it feasible w/o upsetting the CRUSH applecart? Christian -- Christian Balzer Network/Systems Engineer chibi@xxxxxxx Global OnLine Japan/Fusion Communications http://www.gol.com/ _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
 |