Through extensive testing with Optane cache drives, I have been able to increase Queue 1, IO-Depth 1, 4K writes by over 4X using RBD Persistent Write Log Cache. However, krbd does not support pwl, only librbd. In addition, librbd allows tuning such as "rbd_read_from_replica_policy = localize" which results in substantial increases in read IOPS. QEMU can use either krbd or librbd, but I haven't determined if it is possible for LXC to use librbd instead of krbd. Is there anyway to use librbd for LXC containers instead of the kernel rbd driver?
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