On Fri, 2 Jun 2017 10:30:46 +0800 jiajia zhong wrote: > hi guys: > > Our ceph cluster is working with tier cache. If so, then I suppose you read all the discussions here as well and not only the somewhat lacking documentation? > I am running "rados -p data_cache cache-try-flush-evict-all" to evict all > the objects. Why? And why all of it? > But It a bit slow > Define slow, but it has to do a LOT of work and housekeeping to do this, so unless your cluster is very fast (probably not, or you wouldn't want/need a cache tier) and idle, that's the way it is. > 1. Is there any way to speed up the evicting? > Not really, see above. > 2. Is evicting triggered by itself good enough for cluster ? > See above, WHY are you manually flushing/evicting? Are you aware that flushing is the part that's very I/O intensive, while evicting is a very low cost/impact operation? In normal production, the various parameters that control this will do fine, if properly configured of course. > 3. Does the flushing and evicting slow down the whole cluster? > Of course, as any good sysadmin with the correct tools (atop, iostat, etc, graphing Ceph performance values with Grafana/Graphite) will be able to see instantly. Christian -- Christian Balzer Network/Systems Engineer chibi@xxxxxxx Rakuten Communications _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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