performance

uptime

10:13:46 up 1 day, 22:09, 13 users, load average: 3.73, 3.71, 3.50

displays a system’s virtual memory statistics 10 times at 5 second intervals :

vmstat 5 10

si and so columns show the amount of data being transferred between the system’s swap and its memory.

List tcp ports that are being listened on, along with the name of each listener's daemon and its PID:

netstat -plnt

check disk perfs

dd if=/dev/zero of=/data/nobkp/VTL1/afac bs=64k count=16k conv=fdatasync

iostat -nk

XFS fragmentation :

xfs_db -c frag -r /dev/sda1

http://www.rackspace.com/knowledge_center/article/checking-system-load-on-linux