1. We Are All DevOps

5. Everything is a file

6. Finding Disks
/dev/sdX
/dev/sdX{i}
/dev/disk/by-uuid/98affd0e-9d3e-49c1-
bb66-a60119642462
/dev/disk/by-path/pci-0000:00:07.1-
scsi-0:0:0:0

7. Special Files
/dev/zero
/dev/null
/dev/(u)random
/dev/dsp

8. Poking The Kernel With ProcFS

9. root@keyserver:~# cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family: 6
model : 15
model name: Intel(R) Xeon(R) CPU E7440 @ 2.40GHz
stepping: 1
cpu MHz : 2400.070
cache size: 16384 KB
fpu : yes
fpu_exception : yes
cpuid level : 10
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov
pat pse36 clflush dts acpi mmx fxsr sse sse2 ss syscall nx lm
constant_tsc up arch_perfmon pebs bts rep_good pni ssse3 cx16 lahf_lm
bogomips: 4813.70
clflush size: 64
cache_alignment : 64
address sizes : 40 bits physical, 48 bits virtual
power management:

10. root@keyserver:~# cat /proc/meminfo
MemTotal: 253072 kB
MemFree: 7448 kB
Buffers: 25804 kB
Cached: 52552 kB
SwapCached: 4696 kB
Active: 156728 kB
Inactive: 25292 kB
SwapTotal: 522216 kB
SwapFree: 494832 kB
http://www.redhat.com/advice/tips/meminfo.htm

11. Set Swappyness
echo 0 > /proc/sys/vm/swappiness
echo "vm/swappiness=0" >>
/etc/sysctl.conf

12. Hotadd CPU
echo 1 > /sys/devices/system/cpucpu2/online

13. Getting By On The CLI

14. Don't Know A Command? - Apropos

15. How Apropos

17. Use Screen
● Survive disconnects
● Multiple sessions
● Split screen
● Share Screens

19. Get Bash Completion
tomh$ brew install bash-completion
# ~/.bash_profile
if [ -f `brew --prefix`/etc/bash_completion ]; then
. `brew --prefix`/etc/bash_completion
fi
tomh$ ln -s `brew
--prefix`/Library/Contributions/brew_bash_completion.sh `brew
--prefix`/etc/bash_completion.d/

20. Using It

21. Performance Tools

22. top

23. iostat

25. vmstat

26. free

27. Finding Files

28. Find – Old Files
find /path/to/files* -mtime +NUMDAYS

29. Find – Big Files
find / -type f -size +200M

30. Found it? Do stuff to it
find / -type f -size +200M -exec ls -lh {} ;

31. locate

33. xargs
ps ax | grep apache | awk '{ print $1 }' | xargs kill

34. Sed and Awk
● Can do lots with them
● By lots I mean anything
● You probably don't want to write a Energy Price
Comparison site in them

35. Files and File Handles

36. Make a file
root@ubuntu-vm:/home/tom# mkdir /mnt/1G
root@ubuntu-vm:/home/tom# mount /dev/sdb /mnt/1G/
root@ubuntu-vm:/home/tom# cd /mnt/1G/
root@ubuntu-vm:/mnt/1G# dd if=/dev/urandom of=500M bs=1M
count=500
500+0 records in
500+0 records out
524288000 bytes (524 MB) copied, 100.04 s, 5.2 MB/s

37. Some App Uses It
>>> f = open('/mnt/1G/500M')

38. You Remove It
root@ubuntu-vm:/mnt/1G# rm 500M
root@ubuntu-vm:/mnt/1G# ls
.lost+found

39. du is blind
root@ubuntu-vm:/mnt/1G# du -hs .
20K .

40. df can see
root@ubuntu-vm:/mnt/1G# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda1 19G 3.0G 15G 17% /
none 243M 208K 243M 1% /dev
none 249M 168K 249M 1% /dev/shm
none 249M 108K 249M 1% /var/run
none 249M 0 249M 0% /var/lock
/dev/sdb 1008M 534M 424M 56% /mnt/1G

41. lsof to the rescue
root@ubuntu-vm:/mnt/1G# lsof | grep /mnt/1G
bash 1857 root cwd DIR 8,16 4096 2 /mnt/1G
bash 1946 tom cwd DIR 8,16 4096 2 /mnt/1G
bash 1985 tom cwd DIR 8,16 4096 2 /mnt/1G
python 2007 tom cwd DIR 8,16 4096 2 /mnt/1G
python 2007 tom 3r REG 8,16 524288000 12
/mnt/1G/500M (deleted)
su 2011 root cwd DIR 8,16 4096 2 /mnt/1G
bash 2020 root cwd DIR 8,16 4096 2 /mnt/1G
lsof 2176 root cwd DIR 8,16 4096 2 /mnt/1G
grep 2177 root cwd DIR 8,16 4096 2 /mnt/1G
lsof 2178 root cwd DIR 8,16 4096 2 /mnt/1G

42. logrotate

43. Send A Signal
/var/log/httpd/*log {
missingok
notifempty
sharedscripts
postrotate
/bin/kill -HUP `cat /var/run/httpd.pid`
endscript
}

44. CopyTruncate
/path/to/any/app/*log {
missingok
notifempty
sharedscripts
copytruncate
}

45. nginx does it right

46. You can too
Signal.trap("USR1") {DO_STUFF}

47. Dont kill -9

48. Don't rescue Exception

49. Scheduling Things

50. Cron
/etc/cron.daily/
/etc/cron.hourly/
/etc/cron.monthly/
/etc/cron.weekly/
Puppet
sudo gem install cronedit

51. Using upstart to manage processes

52. root@ubuntu-vm:/etc/init# cat vmware-tools.conf
description "VMware Tools services"
author "VMware, Inc."
# Be sure to block the display managers until our job has
completed. This
# is to make sure our kernel services are running before
vmware-user
# may launch.
start on runlevel [235] or starting gdm or starting kdm or
starting prefdm
stop on runlevel [06]
pre-start exec /etc/vmware-tools/services.sh start
post-stop exec /etc/vmware-tools/services.sh stop

53. start on runlevel [2345]
stop on runlevel [06]
respawn
expect fork
script
export HOME="/home/deploy"
export JAVA_HOME="/usr/lib/jvm/java-6-sun"
export HIVE_HOME="/usr/lib/hive"
export HADOOP_HOME="/usr/lib/hadoop"
HIVE_PORT=10001 $HIVE_HOME/bin/hive --service hiveserver&
HIVE_PORT=10002 $HIVE_HOME/bin/hive --service hiveserver&
HIVE_PORT=10003 $HIVE_HOME/bin/hive --service hiveserver&
HIVE_PORT=10004 $HIVE_HOME/bin/hive --service hiveserver&
HIVE_PORT=10005 $HIVE_HOME/bin/hive --service hiveserver&
end script

54. Stopping Processes Running Amok

55. nice
nice <INCREMENT> <COMMAND>
renice <INCREMENT> <PID>

56. ionice
ionice -c {1/2/3} <COMMAND>
ionice -c {1/2/3} -p <PID>
1: real time
2: for best-effort
3: for idle

57. Installing Applications
● Use system .debs where possible
● Author debs
● PPA
● Compile
● Make own .debs
● Be the PPA

58. Waxing Philosophical
There is one system, not a collection of systems.
The desired state of the system should be a known
quantity.
The "known quantity" must be machine parseable.
The actual state of the system must self-correct to the
desired state.
The only authoritative source for the actual state of the
system is the system.
The entire system must be deployable using source media
and text files

59. Hate SPOF
● 10th
Floor Test
● Big Red Bus

60. Global Ownership
Ops
● Its the network
● It's the storage
● It's the virtualisation
● It's the DB
Dev
● It's the JS
● It's the DB

61. Nirvana
● There are no Ops
● Puppet is probably involved

62. Links
● http://aperiodic.net/screen/quick_reference
● http://www.planetdevops.net/
● http://blog.websages.com/2010/12/10/jameswhite-manif