dstat – versatile tool for generating system resource statistics
strace – trace system calls and signals
iotop – simple top-like I/O monitor
iostat – Report Central Processing Unit (CPU) statistics and input/output statistics for devices, partitions and network filesystems (NFS).
vmstat – Report virtual memory statistics
iotop – simple top-like I/O monitor
nfsstat – list NFS statistics
ps – report a snapshot of the current processes.
collectl
/proc /sys