The command for automatic backup

#On the rsync server [192.168.1.29].
touch /var/log/rsyncd.log

#Add the following lines to /etc/rsyncd.conf file.
motd file = /home/rsync/welcome.msg
log file = /var/log/rsyncd.log
use chroot = yes
[server_bkp]
path = /var/www/html
comment = Default rsync module
read only = yes
list = yes
uid = root
gid = root
max connections = 20

#Allowable client machines. Comma separated list.
hosts allow = 192.168.1.70

#Now restart the rsync daemon.
rsync –daemon

#On the client side [192.168.1.70].
mkdir /backup/html

#Set crontab for the backup.
crontab -e
#30 11 * * * /usr/bin/rsync -aqz 192.168.1.29::server_bkp /backup/html

For more information please visit http://rsync.samba.org

 apt-get install git-core 

Run once to create your local work branch

git checkout -b  

Then make changes and commit to local branch.

Commit good practices:

• If you commit with git-gui, please inspect diff of every file included in the commit. You should not modify or delete any files that are not part of logic changes related to a task.
  If you do not have a gui program to commit, inspect diff from command line: git-status – check files that need to be added/removed and git-diff to inspect changed files.
• Enter a good description for commit: first line should be a  summary up to 80 chars, other lines can contain more descriptive message, if commit is related to a ticket use re #ticket_number to automatically add a comment to the ticket with commit description.

To push to repository:

rake git:push

this command will update code from remote repository and will rebase your work branch with master, merge master branch  and it will push your changes to remote server.

To update the code from central repository

rake git:update

git checkout master
git checkout -b  

commit your changes and after push this branch to remote

git push origin  

• You want to copy one commit from other branch to current branch

  git checkout current_branch
  git cherry-pick sha_id_from_other_branch
  

  Using gitk: 

  1. right click on current branch and click check out this branch from popup menu
  2. click on commit from other branch, right-click and select Cherry-pick this commit
• You forget to add some files to previous commit:

  git reset --soft HEAD^
  # do some changes, add files that you forget
  git commit -c ORIG_HEAD
  

  Using git-gui:

  1. Click Amend radio button above text area for commit description
  2. Add/remove files from commit
  3. Commit new changes

You can find more information regarding the Git here.
You can also find some useful miscellaneous git tools here

2 Command to burn a cd image to CD.
cdrecord -v speed=20 dev=/dev/scd0 /root/pfSense-1.2-RC3-LiveCD-Installer.iso

3 Command to make DVD image.
dd if=/dev/scd0 of=/root/Desktop/fedora.iso
cd /root/fc10

4 To make bootable iso of a directory.
mkisofs -J -R -o /opt/fc10.iso -b isolinux/isolinux.bin -c isolinux/boot.cat -no-emul-boot -boot-load-size 4 -boot-info-table /root/fc10

5 To make iso of a directory.
mkisofs -r -o /tmp/var-www-disk1.iso /var/www

6 To make a data dvd.
growisofs -Z /dev/scd0 -R -J /home/happyuser
growisofs -Z /dev/dvd -R -J /some/files

7 Converting avi to DVD and burning the DVD.
mencoder -oac lavc -ovc lavc -of mpeg -mpegopts format=dvd -vf scale=720:576,harddup -srate 48000 -af lavcresample=48000 -lavcopts vcodec=mpeg2video:vrc_buf_size=1835:vrc_maxrate=9800:vbitrate=5000:keyint=15:aspect=16/9:acodec=ac3:abitrate=192 -ofps 25 -o your_video.mpg your_video.avi
dvdauthor -o Memento -x dvd.xml
mplayer dvd:// -dvd-device ./Memento/
growisofs -dvd-compat -Z /dev/dvdrw -dvd-video ./Memento/

8 To format DVD-RW
dvd+rw-format -force /dev/dvd

9 To create ISO images of directories on your hard drive.
mkisofs -o Directory.iso Directory

10 To format CD-RW
cdrecord blank=fast dev=1,0,0

11 To create an empty disk image, to be used as the disk for an emulator for example, one can get data from /dev/zero. To create a 10mb image:
dd if=/dev/zero of=myimage bs=1024 count=10240

12 To merge more than one avi files.
avimerge -o filename.avi -i first_file.avi second_file.avi

13 To convert avi to mpeg-2
mencoder /root/ItalianJob.avi -mf fps=1 -o /opt/ItalianJob.mpg -ovc lavc -oac pcm -lavcopts vcodec=mpeg2video

14 To convert mpg to avi.
mencoder /editor/Seval.mpg -ovc xvid -oac mp3lame -xvidencopts bitrate=800 -o /opt/Seval.avi

15 To convert all jpeg files in the current directory to avi.
mencoder “mf://*.jpg” -mf fps=1 -o outputs.avi -ovc lavc -lavcopts vcodec=mpeg4

2. Check /tmp permissions. /tmp should be chmod 1777

3. Check /tmp ownership /tmp should be owned by root:root

4. Check /etc/cron.daily/logrotate for /tmp noexec workaround. Due to a bug in logrotate if /tmp is mounted with the noexec option, you need to have logrotate use a different temporary directory. If you don’t do this syslog may not restart correctly and will write to the wrong (older) log files.

5. Check /var/tmp permissions. /var/tmp should be chmod 1777

6. Check /var/tmp ownership. /var/tmp should be owned by root:root

7. Check /var/tmp is mounted as a filesystem. /var/tmp should either be symlinked to /tmp or mounted as a filesystem

8. Check /var/tmp is mounted noexec,nosuid. /var/tmp isn’t mounted with the noexec,nosuid options (currently: none). You should consider adding a mountpoint into /etc/fstab for /var/tmp with those options

9. Check /usr/tmp permissions. /usr/tmp should be chmod 1777

10. Check /usr/tmp ownership. /usr/tmp should be owned by root:root

11. Check /usr/tmp is mounted as a filesystem or is a symlink to /tmp. /usr/tmp should either be symlinked to /tmp or mounted as a filesystem.
Check /etc/resolv.conf for localhost entry. You should not specify 127.0.0.1 or localhost as a nameserver in /etc/resolv.conf – use the servers main IP address instead

12. Check /etc/named.conf for recursion restrictions. If you have a local DNS server running but do not have any recursion restrictions set in /etc/named.conf this is a security and performance risk and you should look at restricting recursive lookups to the local IP addresses only. Unrestricted recursive lookups are as good as a DDoS attack against your system. They will eat up all your system resources

13. Check server runlevel. For a secure server environment you should only run the server at runlevel 3. You can fix this by editing /etc/inittab and changing the initdefault line to:
id:3:initdefault: and then rebooting the server.

14. Check nobody cron. You have a nobody cron log file – you should check that this has not been created by an exploit.

15. Check Operating System support. Make certain that your OS version is still supported by the manufacturer and that upgrades continue to be available.

16. Check SSHv1 is disabled. You should disable SSHv1 by editing /etc/ssh/sshd_config and setting: Protocol 2 (remove the hash # from in front of the line and edit out the 1.1)

17. Check SSH on non-standard port. Moving SSH to a non-standard port avoids basic SSH port scans. Edit /etc/ssh/sshd_config and setting: Port nnnn Where nnnn is a port of your choosing. Don’t forget to open the port in the firewall first!

18. Check SSH PasswordAuthentication. For ultimate SSH security, you might want to consider disabling PasswordAuthentication and only allow access using PubkeyAuthentication.

19. Check telnet port 23 is not in use. Close this port in your firewall. Telnet is an insecure protocol and you should disable the telnet daemon if it is running

20. Check shell resource limits. You should enable shell resource limits to prevent shell users from consuming server resources – DOS exploits typically do this. If you are using cPanel/WHM set Shell Fork Bomb Protection.

21. Disable all instances of IRC – BitchX, bnc, eggdrop, generic-sniffers, guardservices, ircd, psyBNC, ptlink. If you are using WHM you can do this in the Background Process Killer.

22. Check apache for mod_security if not installed install it from source.

23. Check apache for mod_evasive. You should install the mod_evasive apache module from source to help prevent DOS attacks against apache. Note that this module breaks FrontPage functionality.

24. Check apache for RLimitCPU. You should set a value RLimitCPU to prevent runaway scripts from consuming server resources – DOS exploits can typically do this.

25. Check apache for RLimitMEM. You should set a value RLimitMEM to prevent runaway scripts from consuming server resources – DOS exploits can typically do this.