Let's benchmark single disk write performance:
- Drop caches:
# echo 3 > /proc/sys/vm/drop_caches
- Use dd to write a file named deleteme of the size 10G, filled with zeros /dev/zero as the input file to the directory where Ceph OSD is mounted, that is, /var/lib/ceph/osd/ceph-0/:
# dd if=/dev/zero of=/var/lib/ceph/osd/ceph-0/deleteme
bs=10G count=1
oflag=direct
Ideally, you should repeat step 1 and step 2 a few times and take the average value. In our case, the average value for write operations comes to be 121 MB/s, as shown in the following screenshot:
