Debian Linux Distribution Reference
Contents
Installation
Debian Linux distribution Codenamed Jessie was released April 25, 2015.
The installer boot screen looks like this:
Installer boot menu Install Graphical install Advanced options > Help Install with speech synthesis
Kernel Selection: linux-image-486, linux-image-586, linux-image-686-pae are all meta packages which will install one of the these two: linux-image-3.16.0-4-586 and linux-image-3.16.0-4-686-pae
The advantage to the meta package is that it will ensure that the kernel gets a release (version) upgrade - in a stable release this is not so important, but it's best to install the meta package anyway.
585 kernel is for older 586 class CPUs while 686-pae is for newer 686 class CPUs with PAE/NX bit support. Find out if your CPU support PAE/NX and install the relevant kernel meta package.
PAE stands for Physical Address Extension. Normally a 32-bit OS will only be able to access 4GB of RAM while essentially using only 3GB. PAE enables 32-bit processors to access more than 4GB RAM. NX stands for No Execute page protection. NX processor bit allows the processor to help and safeguard PC from malicious attacks. See Technize.net for more info.
Package Mirror: During install you will be asked what mirror to pull additional packages from. You can use ftp.debian.org although you should note that ftp.debian.org is not canonical location of Debian packages, instead it is merely one of several servers that get updated from an internal Debian server.
Latest Update: Debian 9.7 was released January 23rd, 2019. (The seventh point release, 9.7). Support for 64 and 32 bit PCs. Stretch includes over 15346 new packages. Improvements include
- LibreOffice is upgraded to version 5.2;
- Calligra is upgraded to 2.9.
- Evolution 3.22.
- MariaDB is now the default MySQL version 10.1.
- Xorg no longer requires root!
Networking Change in Stretch
Instead of eth0, eth1, etc the twits changed it to use the firmware/BIOS provided index numbers and PCI card slot numbers, producing names like ens0 or enp1s1 (ethernet) or wlp3s0 (wlan). Note that upgrades of jessie systems won't change the old interface names!
Configuration
Remote Connection
Install sshd to allow remote secure shell connection to the terminal. Once installed and running sshd will allow you to remote connect. The SSH server can be selected for install during the installation of the operating system, or it can be added afterwards using the command "apt install openssh-server" at the command line.
The latest Debian "Jessie" distribution uses version 6.7p1-1 of OpenSSH which has been released with legacy "insecure" ciphers disabled by default. If trying to use an old secure terminal software you might find that the cipher is no longer permitted. You can Enable Legacy Cipher in Linux for SecureCRT but be advised that this will put the security of your machine at risk. For an internal LAN server it is not a big deal, but enabling insecure ciphers on an Internet attached machine is not advised.
Customization
terminal and shell login messages
I want to disable the notification about new mail when I login to a shell:
To do this for all system users simply modify /etc/pam.d/sshd
vi /etc/pam.d/sshd
Modify this section to look like this
# Print the status of the user's mailbox upon successful login. #session optional pam_mail.so standard noenv # [1] session optional nopen noenv
I remarked out the default line with a POUND # character and below added a custom line telling it not to check for new mail messages on login. Another option to do it on a per-user basis is to use the .bashrc file (for login shell) or .bash_profile and add
unset MAILCHECK
One option or the other works, you won't need to do both.
See our notes on the difference between a login and non-login shell.
