Hello,
which Linux command line tool is your favorite for discovering high load cause on the server?
In my case "htop" as it allows easy sorting of the processes according to memory used, CPU usage and disk activity. The disk activity has to be manually set in configuration, it is named "IO_RATE -> IORW" and it is read+write rate in bytes per second. But it do not shows transactions per second. I have NOT found any tool that shows per process IOPS/TPS.
nmon and then "ldn" keys. it will show cpu, disk, network utilization. It shows "Transfers/sec" which should be rough estimate of IOPS, but it shows around 1000 in my case and i got just 2x 7K RPM drives in HW raid 1, so not sure if this is anyhow useful.
iotop -ao is my next favorite, because frequently HDD IO is the high load cause. It shows cumulative IO stats for the processes.
glances and then "i" key to sort by io
iostat -x 5 shows cpu and disk utilization, values like %iowait, r/s, w/s (reads/writes per seconds - IOPS), HDD utilization in percent. Does not show per process utilization.
I hope you can share some other tools that was not yet mentioned.