Hi Andrei, These are good questions. We have another cluster with filestore and bcache but for this particular one I was interested in testing out bluestore. So I have used bluestore both with and without bcache. For my synthetic load on the vm's I'm using this fio command: fio --randrepeat=1 --ioengine=libaio --direct=1 --gtod_reduce=1 --name=test --filename=test --bs=4k --iodepth=64 --size=4G --readwrite=randwrite --rate_iops=50 Currently on bluestore with my synthetic load I'm getting 7% hit ratio (cat /sys/block/bcache*/bcache/stats_total/cache_hit_ratio) On our filestore cluster with ~700 vm's of varied workload we're geting about 30-35% hit ratio. In the hourly hit ratio I have as high as 50% on some osd's in our filestore cluster. Only 25% on my synthetic load on bluestore so far, but I hadn't actually been checking this stat until now. I hope that helps. Regards, Richard > Hi Richard, > It is an interesting test for me too as I am planning to migrate to > Bluestore storage and was considering repurposing the ssd disks > that we currently use for journals. > I was wondering if you are using the Filestore or the bluestone > for the osds? > Also, when you perform your testing, how good is the hit ratio > that you have on the bcache? > Are you using a lot of random data for your benchmarks? How > large is your test file for each vm? > We have been playing around with a few caching scenarios a > few years back (enchanceio and a few more which I can't > remember now) and we have seen a very poor hit ratio on the > caching system. Was wondering if you see a different picture? > Cheers _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
 |