Unix / Linux Cheat Sheet Debian/Ubuntu

Table of Contents

current users

  • Determine who you are currently:
    • id
    • whoami
  • Determine who's logged into he server
    • who


  • Mounting a share on a domain:
    • `sudo smbmount //target/share /localdir -o username=username/domain`
  • Unmounting a samba share:
    • `sudo umount /localdir`



  • Decent date stamp command:
    • date +%y%m%d%H%M%S


Formats a line of text, just like the gqip command in Vim.


On AIX and solaris, this is a good example of how to use the find command to find large files:

  • verbose output
    • find . -size +100000000c -ls
  • terse output
    • find . -size +100000000c -prune


  • Show number of processors:
    • lscfg | grep proc | wc -l


  • Passing a shell var into an awk script.
$ awk 'script' var=$shell_var
  • Example - Find all child process of a given executable name, such as /usr/bin/foo
$ pid=$(ps -e -o pid,args | \
        grep /usr/bin/foo | \
        grep -v grep | \
        awk '{print $1}')
$ child_pids=$(ps -e -o pid,ppid | \
        awk '{if ($2 == pid) print $1}' pid=$pid)
$ echo $child_pids


Increasing The Size Of A Logical Volume

  • Add your disk to the machine
  • Format disk as LVM partition
  • Convert your new partition into a physical volume
    • sudo pvcreate /dev/xxx1
  • Add your new physical volume to a volume group
    • sudo vgextend vgmain /dev/xxx1
  • Increase the size of your logical volume
    • lvextend -l+2384 /dev/vgmain/lvhome
  • Increase the size of your filesystem
    • xfsgrowfs /home


What To Update When Your VMWare IP Address Changes

  • Change any mappings in your windows host file
  • Change any ip addresses for that server in your putty conf if necessary
  • Change your hostname's ip address in /etc/hosts
  • Change your gateway ip address in /etc/conf.d/net

Portage Best Practices

  • Instead of using USE flags with emerge, edit /etc/portage/package.use
    • For example:
      • net-irc/xchat -perl -python
      • net-p2p/bittornado -gtk
      • www-client/mozilla-firefox java mozdevelop

Kernel Upgrade Process

  • module-rebuild populate
  • If you're upgrading to a different "r" number:
    • cd /etc/kernels
    • cp kernel-config-x86-2.6.9-gentoo-rX kernel-config-x86-2.6.9-gentoo-rX
  • genkernel –menuconfig –bootloader=grub all
  • Fix vmware
    • cd /opt/vmware/workstation/tools/bin
    • sudo ./vmware-config-tools.pl
    • sudo rmmod pcnet32
    • sudo rmmod vmxnet
    • sudo depmod -a
    • sudo modprobe vmxnet
    • sudo /etc/init.d/net.eth0 restart
    • sudo /etc/init.d/sshd start
  • reboot
  • module-rebuild rebuild

encrypted backups

Here's the command that I used to try and backup my home partition to dreamhost:

nice -n 19 tar czvf - --listed-incremental --exclude='Movies' --exclude='Music' \
    ~/main_backup.snar /mnt/ieee1394/snapshots/daily.0/localhost/home | openssl \
    enc -des3 -salt -pass file:/home/tom/.ssl/secret.txt | ssh tompurl@bogus.dreamhost.com \
    "( split -b 256m - /home/tompurl/backup/homer-home/main_backup-full.tgz.enc )"

Installing The JDK On Ubuntu

Setting up DNS Suffixes

  • Open /etc/dhcp3/dhclient.conf
  • Add the following
    • supersede domain-name "svr.foo.net foo.net ad.foo.net";
  • Restart networking

Turning Off CD Autorun on Xubuntu

  • Install gnome-volume-manager
  • Open gnome-volume-properties app
  • Shut off all autostart/automount features.

Installing VMWare Tools on 6.06 Server

$ sudo apt-get install build-essential linux-source linux-headers-`uname -r`
$ normal manual procedure
(( necessary to use vmware-toolbox ))
$ sudo apt-get install xclock libxi6

Installing BeautifulSoup on Ubuntu 6.06 Server

$ sudo apt-get install python2.4-dev python2.4-setuptools

Upgrading Your Kernel on 6.06 Server

$ sudo aptitude dist-upgrade
$ sudo aptitude install linux-headers-(( results of uname -r for new kernel ))
$ sudo shutdown -r now
(( from console ))
$ sudo vmware-config-tools.pl
(( choose all defaults ))
$ sudo /etc/init.d/networking stop
$ sudo rmmod pcnet32
$ sudo rmmod vmxnet
$ sudo depmod -a
$ sudo modprobe vmxnet
$ sudo /etc/init.d/networking start

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