This article will help you collect IO statistics to determine how active your disks are. This can help you determine feasibility of WAN replication using DRBD Proxy.
A full week of iostat data should provide a good sample:
# iostat -m 60 10080 -t -y > ~/iostat.rpt
Then get the average (grep for backing, ‘dm-7’ in this case):
$ count=0; total=0; for i in $(grep dm-7 ~/iostat.rpt | awk '{ print $4; }'); do
total=$(echo $total+$i | bc ); ((count++)); done; echo "scale=2; $total / $count" | bc
Another example for collecting and calculating averages using awk:
# iostat -xymt dm-7 300 288 > ~/iostat.rpt
We can then awk that file to get us the average write throughtput for the sample period like so:
# grep dm-0 /tmp/iostat-output.txtt | awk '$1 {sum += $7} END {print sum / NR}'
If the average write throughput is far greater than your average WAN network throughput, then you might not be able to utilize DRBD® and DRBD Proxy for DR (disaster recovery) replication offsite.
Reviewed 2020/12/01 – DGT