Hi everyone, I wonder if CephFS is able to read from all replicas simontaniously, that will result in doubled read performance if a replica of 2 has been used. I have done some humble testing on 5PCs (2OSD (each on 1PC) + 1MON/MDS PC + 2 CephFS clients). I have did two configurations: 1) default from ceph-deploy, replication 2, 4MB objects with 1 stripe count and 4MB stripe size. 2) custom conf without replication, 4MB object with 4 stripe count and 1MB stripe size. If replication is used write performance is around 30MB/s and read 100MB/s. If not write is around 55MB/s and read is suprisingly lower 95MB/s. I would expect to be around 160 or 180 since i have used two hard drives. journal was on the same OSD So i think with replication the data was served from both replicas, but im not sure. I have tried to find some more information about this but couldnt find any. I have one last question. Does journals impact read performance? I mean if journal is on the same OSD, the write performance is two times slower because write is done to journal and then onto OSD. Does something simalar happen for reads to? I think not coz it seems silly to me. Thanks for any replyes. Michal --- Tato zpr?va neobsahuje viry ani jin? ?kodliv? k?d - avast! Antivirus je aktivn?. http://www.avast.com
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