This is a draft cheat sheet. It is a work in progress and is not finished yet.
Outbound Network Traffic on eth0
Tools |
netem, tc, qdisc, iptables |
Add delay 1000+-10ms to all packets to box 10.0.0.2 |
#tc qdisc add dev eth0 root handle 1: prio
#tc qdisc add dev eth0 parent 1:3 handle 30: netem delay 1000ms 10ms distribution normal
#tc filter add dev eth0 protocol ip parent 1:0 prio 3 u32 match ip dst 10.0.0.2/32 flowid 1:3 |
Use netem to emulate loss, duplication and corruption |
#tc qdisc change dev eth0 handle 30: netem loss 0.1%
#tc qdisc change dev eth0 handle 30: netem duplicate 1%
#tc qdisc change dev eth0 handle 30: netem corrupt 0.1% |
Cleanup |
#tc qdisc del dev eth0 root |
All commands should be run as root
Inbound Network Traffic on eth0
Tools |
netem, tc, qdisc, iptables |
Notes: |
To use netem on incoming traffic we have to use ifb (intermediate functional block pseudo-device). This network device allows attaching queuing discplines to incoming packets. |
To load and brinnig up ifb module |
#modprobe ifb
#ip link set dev ifb0 up |
Add delay 1000+-10ms to all packets from box 10.0.0.2 |
#tc qdisc add dev eth0 ingress
#tc filter add dev eth0 parent ffff: protocol ip u32 match ip src 10.0.0.2/32 flowid 1:1 action mirred egress redirect dev ifb0
#tc qdisc add dev ifb0 root netem delay 1000ms |
Use netem to emulate loss, duplication and corruption |
#tc qdisc change dev ifb0 root netem loss 0.1%
#tc qdisc change dev ifb0 root netem duplicate 1%
#tc qdisc change dev ifb0 root netem corrupt 0.1% |
Cleanup |
#tc qdisc del dev eth0 ingress
#tc qdisc del dev ifb0 root |
All commands should be run as root
Simulate Network Cable pull
Block all traffic except SSH |
#iptables -A INPUT -i lo -j ACCEPT
#iptables -A INPUT -p tcp -m tcp --dport 22 -j ACCEPT
#iptables -A OUTPUT -o lo -j ACCEPT
#iptables -A OUTPUT -p tcp --sport 22 -m state --state ESTABLISHED -j ACCEPT
#iptables -P INPUT DROP
#iptables -P OUTPUT DROP |
Cleanup/Flush all rules |
#iptables -F |
All commands should be run as root in right order
It is better to place in script
Python Script to use X MB of memory on Server
#!/usr/bin/env python
import sys
import time
if len(sys.argv) != 2:
print "usage: fillmem <number-of-megabytes>"
sys.exit()
count = int(sys.argv[1])
megabyte = (0,) (1024 1024 / 8)
data = megabyte * count
while True:
time.sleep(1)
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Credit swiftcoder on stackexchange
Fill up disk space on server
dd - non readable - 1GB file |
#dd if=/dev/zero of=file.txt count=1024 bs=1048576 |
dd - random - readable - 1GB file |
#dd if=/dev/urandom of=file.txt bs=1048576 count=1024 |
stress
Use 1GB of Memory for 1 hour |
stress --vm 2 --vm-bytes 1024M --vm-hang 3600 |
Use 4 CPUs calculating sqrt of randint for 1 hour |
stress --cpu 4 --timeout 3600 |
Stress IO |
stress --io 4 |
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