-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 On Mon, Sep 21, 2015 at 3:02 AM, Wouter De Borger wrote: > Thank you for your answer! We will use size=4 and min_size=2, which should > do the trick. > > For the monitor issue, we have a third datacenter (with higher latency, but > that shouldn't be a problem for the monitors) Just be sure that the IP address in the third DC is higher than the other two. Ceph chooses the lowest IP address as the primary monitor. Having the monitor with the highest latency as your primary is sure to give you grief. > We had also considered the locality issue. Our WAN round trip latency is 1.5 > ms (now) and we should get a dedicated light path in the near future (<0.1 > ms). > So we hope to get acceptable latency without additional tweaking. > The plan B is to make two pools, with different weights for the different > DC's. VM's in DC 1 will get high weight for DC 1, VM's in DC 2 will get high > weight for DC 2. You don't want to mess with weights or else you will get stuck PGs because there isn't enough storage at the remote DC to hold all your data or the local DC fills up faster or CRUSH can't figure out how to distribute balanced data in an unbalanced way. You will probably want to look at primary affinity. This talks about SSD, but the same principle applies http://www.sebastien-han.fr/blog/2015/08/06/ceph-get-the-best-of-your-ssd-with-primary-affinity/ - ---------------- Robert LeBlanc PGP Fingerprint 79A2 9CA4 6CC4 45DD A904 C70E E654 3BB2 FA62 B9F1 -----BEGIN PGP SIGNATURE----- Version: Mailvelope v1.1.0 Comment: https://www.mailvelope.com wsFcBAEBCAAQBQJWAA80CRDmVDuy+mK58QAAK2UQAIadviUNo+hybghYO2de 0Ayqy1SQ9hPjpwJUTWt0VKIgIoDMMbp1+LVd6EiPRNXPPwalDZen8z1ARW5F o0g0nxMkJIJWxY2U3ch4s3oE85Hl5NqyPZIdaLfqQv7PXfFsRTM7rZDMRuLn X9PWcxzZ3lvXj6WA/jiN42zXlhTlhLhtKV153poCtd/iCkytJUEPZF/c+Pr+ /mIVVbbtzPDh5XC/Il/KEI1W+fZzPG27EL6N2YoskYWTEpUr0auBH7jTLm8B kk4HKZToBsakP/j/LEhrh+MMW/ZNwuUaigWe351YQrkmlUBXxKVtnlgfJpDL KIGvVDICRMwe6e3ubU7umsiFVchYPBlXFN3OoRmx3UfPp3WlfKong+PG9X8+ JoukMyj630jmaDy7KPH5sKv+LUaLpWlWv6271bVUDlSMjPNHqVMlk/HsOGit QYaWQQygQ+D/YedLP66xz+O6A8qfmrYfWBZZDdG9C49erw6Q6Ihzp6u+Hj1O zt96JsmBjHcq27AfK1jSbZDGOHchL78/Ok3O4O01tC00HwRvQLy/ofppOzgn KHnuLMs/9fZpSqh5sZ1BxWSgKBnYzc3npFloaOZLoVPT4Dv+hM8kL9lF0mHm 3j1D4ZmysVaSU+zVw0WsWaNVQyrrPn+i9ivT6U/3VHiaS2Nz+BQTQeq0oMqQ awOM =sl/W -----END PGP SIGNATURE----- _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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