mounted rbd images slower than librbd
With dd on a mounted rbd images the total network usage caps at 4Gb/s with rbd bench the total network usage caps at 7Gb/s
- ls /dev/rbd/ro > /tmp/l
- 7Gb/s: shuf -n 15 /tmp/l | while read i ; do rbd --pool ro bench --io-size 4M --io-type read --io-pattern seq --io-threads 1 --io-total 100G $i >& $i.out & echo $i ; done
- 4Gb/s: shuf -n 10 /tmp/l | while read i ; do dd if=/dev/rbd/ro/$i bs=4096K status=progress of=/dev/null >& $i.out & echo $i ; done