I'm wondering if anyone has some tips for managing different types of pools, each of which fall on a different type of OSD. Right now, I have a small cluster running with two kinds of OSD nodes, ones with spinning disks (and SSD journals) and another with all SATA SSD. I'm currently running cache tiering and looking to move away from that. My end goal is to have a general purpose block storage pool on the spinning disks along with object storage. Then I'd like to do a separate pool of low-latency block storage against the SSD nodes. Finally, I'd like to add a third node type that has a high number of spinning disks, no SSD journals and runs object storage on an EC pool. This final pool would be for backup purposes. I can envision running all these in the same cluster with a crushmap that allocates the pools to the correct OSDs. However, I'm concerned about the radius of failure running all these different use cases on a single cluster. I have for example, had an instance where a single full OSD caused the entire cluster to stop accepting writes, which affected all the pools in the cluster, regardless of whether those pools had PGs on the affected OSD. It's simple enough to run separate clusters for these, but then I'd be faced with that complexity as well, including some number of mons for each. I'm wondering if I'm overstating the risks and benefits of having a single crushmap. i.e. instead of cache tiering, I can do a primary SSD secondary and tertiary on spinning disk. Any thoughts and experiences on this topic would be welcome. -H _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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