Interestingly, I have found that if I limit the rate at which data is written the tiering behaves as expected. I'm using a robocopy job from a Windows VM to copy large files from my existing storage array to a test Ceph volume. By using the /IPG parameter I can roughly control the rate at which data is written. I've found that if I limit the write rate to around 30MBytes/sec the data all goes to the hot tier, zero data goes to the HDD tier, and the observed write latency is about 5msec. If I go any higher than this I see data being written to the HDDs and the observed write latency goes way up. _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx