tcpdump a virtual interface of a vm:

# call <scriptname> <vm name>
if [ "$1" == "" ]; then
    echo no vm given
    exit 1
fi
echo tcpdump vm $1
tcpdump -i vif$(xe vm-list name-label=$1 params=dom-id --minimal).$(xe vif-list vm-name-label=$1 params=device --minimal) -w tcpdump-$1-$(date +%y%m%d%H%M%S)_ -n -s 0 -C 100 -K -v

To reset your AD connection, if some domain user can't login anymore, reset the lsassd:

service lsassd restart

list_domains -all

Show cpu stats every 2 seconds

mpstat 2

Show all cpus stats

mpstat 2 -P ALL

Show memory stats every 2 seconds with unit size M(egabyte)

vmstat 2 -S M

tload prints a graph of the current system load average every 2 seconds

tload -d 2

If you want to change the scale, use -s

tload -d 2 -s 8

The “*” are the load average and “-” mease the units in the scale. “=” is used if the load average is at the unit line or higher.