We use write-around cache tier with libradosstriper-based clients. We faced
with bug which causes performance degradation:
http://tracker.ceph.com/issues/22528 . Especially if it is a lot of small
objects - sizeof(1 striper chunk). Such objects will promote on every
And it is very hard to benchmark cache tier.
Also, we have a little testing pool with rbd disks for vm's. It works better
with cache tier on ssd's. But, there's no heavy i/o load.
It's better to benchmark cache tier for your special case and choose cache mode
based on benchmark results.
06.03.2018, 02:28, "Budai Laszlo" <laszlo.bu...@gmail.com>:
> Dear all,
> I have some questions about cache tier in ceph:
> 1. Can someone share experiences with cache tiering? What are the sensitive
> things to pay attention regarding the cache tier? Can one use the same ssd
> for both cache and
> 2. Is cache tiering supported with bluestore? Any advices for using cache
> tier with Bluestore?
> Kind regards,
> ceph-users mailing list
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