Part I Common tasks #
- 1 Bash and Bash scripts
Today, many people use computers with a graphical user interface (GUI) like GNOME. Although GUIs offer many features, they're limited when performing automated task execution. Shells complement GUIs well, and this chapter gives an overview of some aspects of shells, in this case the Bash shell.
- 2
sudo
basics Running certain commands requires root privileges. However, for security reasons and to avoid mistakes, it is not recommended to log in as
root
. A safer approach is to log in as a regular user, and then usesudo
to run commands with elevated privileges.- 3 Using YaST
YaST is a SUSE Linux Enterprise Server tool that provides a graphical interface for all essential installation and system configuration tasks. Whether you need to update packages, configure a printer, modify firewall settings, set up an FTP server, or partition a hard disk—you can do it using YaST. …
- 4 YaST in text mode
The ncurses-based pseudo-graphical YaST interface is designed primarily to help system administrators to manage systems without an X server. The interface offers several advantages compared to the conventional GUI. You can navigate the ncurses interface using the keyboard, and there are keyboard sho…
- 5 YaST online update
SUSE offers a continuous stream of software security updates for your product. By default, the update applet is used to keep your system up-to-date. Refer to Section 21.5, “The GNOME package updater” for further information on the update applet. This chapter covers the alternative tool for updating …
- 6 Managing software with command line tools
This chapter describes Zypper and RPM, two command line tools for managing software. For a definition of the terminology used in this context (for example,
repository
,patch
, orupdate
) refer to Section 21.1, “Definition of terms”.- 7 System recovery and snapshot management with Snapper
Snapper allows creating and managing file system snapshots. File system snapshots allow keeping a copy of the state of a file system at a certain point of time. The standard setup of Snapper is designed to allow rolling back system changes. However, you can also use it to create on-disk backups of user data. As the basis for this functionality, Snapper uses the Btrfs file system or thinly-provisioned LVM volumes with an XFS or Ext4 file system.
- 8 Live kernel patching with KLP
This document describes the basic principles of the Kernel Live Patching (KLP) technology, and provides usage guidelines for the SLE Live Patching service.
- 9 Transactional updates
Transactional updates are available in SUSE Linux Enterprise Server as a technology preview, for updating SLES when the root file system is read-only. Transactional updates are atomic (all updates are applied only if all updates succeed) and support rollbacks. It does not affect a running system as no changes are activated until after the system is rebooted. As reboots are disruptive, the admin must decide if a reboot is more expensive than disturbing running services. If reboots are too expensive then do not use transactional updates.
Transactional updates are run daily by the
transactional-update
script. The script checks for available updates. If there are any updates, it creates a new snapshot of the root file system in the background, and then fetches updates from the release channels. After the new snapshot is completely updated, it is marked as active and will be the new default root file system after the next reboot of the system. Whentransactional-update
is set to run automatically (which is the default behavior) it also reboots the system. Both the time that the update runs and the reboot maintenance window are configurable.Only packages that are part of the snapshot of the root file system can be updated. If packages contain files that are not part of the snapshot, the update could fail or break the system.
RPMs that require a license to be accepted cannot be updated.
- 10 Remote graphical sessions with VNC
Virtual Network Computing (VNC) enables you to access a remote computer via a graphical desktop, and run remote graphical applications. VNC is platform-independent and accesses the remote machine from any operating system. This chapter describes how to connect to a VNC server with the desktop clients vncviewer and Remmina, and how to operate a VNC server.
SUSE Linux Enterprise Server supports two different kinds of VNC sessions: One-time sessions that “live” as long as the VNC connection from the client is kept up, and persistent sessions that “live” until they are explicitly terminated.
A VNC server can offer both kinds of sessions simultaneously on different ports, but an open session cannot be converted from one type to the other.
- 11 File copying with RSync
Today, a typical user has several computers: home and workplace machines, a laptop, a smartphone or a tablet. This makes the task of keeping files and documents in synchronization across multiple devices all the more important.