Hi,
you need to flush all caches before starting read tests. With fio you
can probably do this if you keep the files that it creates.
as root on all clients and all osd nodes run:
echo 3 > /proc/sys/vm/drop_caches
But fio is a little problematic for ceph because of the caches in the
clients
The same..
see:
A: (g=0): rw=read, bs=5M-5M/5M-5M/5M-5M, ioengine=*libaio*, iodepth=1
...
fio-2.2.10
Starting 16 processes
A: (groupid=0, jobs=16): err= 0: pid=27579: Mon Dec 12 20:36:10 2016
mixed: io=122515MB, bw=6120.3MB/s, iops=1224, runt= 20018msec
I think at the end, the only one way to s
My understanding is that when using direct=1 on a raw block device FIO
(aka-you) will have to handle all the sector alignment or the request will get
buffered to perform the alignment.
Try adding the –blockalign=512b option to your jobs, or better yet just use the
native FIO RBD engine.
Someth
