Your claim that all cache is used for K/V cache is false (with default settings). K/V cache is maximized to 500Meg. : bluestore_cache_kv_max Description: The maximum amount of cache devoted to key/value data (rocksdb). Type: Unsigned Integer Required: Yes Default: 512 * 1024*1024 (512 MB) ----- Original Message ----- From: "David Turner" <drakonstein@xxxxxxxxx> To: "Tyler Bishop" <tyler.bishop@xxxxxxxxxxxxxxxxx> Cc: "ceph-users" <ceph-users@xxxxxxxxxxxxxx> Sent: Friday, August 31, 2018 1:31:37 AM Subject: Re: Best practices for allocating memory to bluestore cache Be very careful trying to utilize more RAM while your cluster is healthy. When you're going to need the extra RAM is when you're closer is unhealthy and your osds are peering, recovering, backfilling, etc. That's when the osd daemons start needing the RAM that is recommended in the docs. On Thu, Aug 30, 2018, 4:21 PM Tyler Bishop < [ mailto:tyler.bishop@xxxxxxxxxxxxxxxxx | tyler.bishop@xxxxxxxxxxxxxxxxx ] > wrote: Hi, My OSD host has 256GB of ram and I have 52 OSD. Currently I have the cache set to 1GB and the system only consumes around 44GB of ram and the other ram sits as unallocated because I am using bluestore vs filestore. The documentation: [ http://docs.ceph.com/docs/master/rados/configuration/bluestore-config-ref/ | http://docs.ceph.com/docs/master/rados/configuration/bluestore-config-ref/ ] list the defaults of ram to be used almost exclusively for the KV cache. With a system like mine do you think It would be safe to allow 3GB cache and change the KV ratio to 0.60? Thanks _____________________________________________ Tyler Bishop EST 2007 O: 513-299-7108 x1000 M: 513-646-5809 [ http://beyondhosting.net/ | http://BeyondHosting.net ] This email is intended only for the recipient(s) above and/or otherwise authorized personnel. The information contained herein and attached is confidential and the property of Beyond Hosting. Any unauthorized copying, forwarding, printing, and/or disclosing any information related to this email is prohibited. If you received this message in error, please contact the sender and destroy all copies of this email and any attachment(s). _______________________________________________ ceph-users mailing list [ mailto:ceph-users@xxxxxxxxxxxxxx | ceph-users@xxxxxxxxxxxxxx ] [ http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com | http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com ] _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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