[ceph-users] Re: Strategy for add new osds

Hi,

as far as I understand it,

you get no real benefit with doing them one by one, as each osd add, can cause a lot of data to be moved to a different osd, even tho you just rebalanced it.

Less than with older releases, but yeah. I’ve known someone who advised against doing them in parallel because one would — for a time — have PGs with multiple remaps in the acting set. The objection may have been paranoia, I’m not sure. One compromise is to upweight the new OSDs one node at a time, so the churn is limited to one failure domain at a time. — aad