On Sat, Mar 9, 2024 at 4:42 AM Nathan Morrison <natemorrison@gmail.com> wrote:
This was asked in reddit and was requested to post here:
So in RBD, say I want to make an image that's got an object size of 1M instead of the default 4M (if it will be a VM say, and likely not have too many big files in it, just OS files mostly). I also know I don't wanna go too crazy and make 4k objects or the cluster will blow up with number of objects. What's a good rule of thumb on what to set the stripe unit and count in relation to object size?
Also how can I see the stripe unit and count for an image, it seems "rbd info <img-name>" doesn't show it, only object size (or order).
Would this be sensible (assuming old img is default 4M obj size) or really stupid and why?
rbd cp --object-size 1M --stripe-unit 1M --stripe-count 1 pool/old-img pool/new-img
Hi Nathan, This (stripe-unit == object-size and stripe-count == 1) is the default, so if you want to change the object size, passing just --object-size is sufficient. Thanks, Ilya