Analyzing disk usage is an important task for Linux admin. Disk I/O bottlenecks can bring down applications. Hope this post can give you more ideas on how to troubleshoot disk problems.
Check Disk Space Usage with df
Check Disk Utilization In Linux
Check Disk IOPS and Bandwidth In Linux
Check IO usage by Process
What does actimeo mean in nfs mount
The "actimeo=0" option means turn attribute caching off. The actimeo option actually makes the time duration the nfs client holds the various cache attributes like "acregmin","acregmax","acdirmin" and "acdirmax" to zero seconds, which means that the nfs client will need to look for the attributes everytime from the server.
DHCP v4 traffic operates on port 67 (Server) and port 68 (Client). So we can capture the appropriate traffic with the following expression. (v4)
tcpdump -i eth0 udp port 67 or port 68 -vvv