Debian

Low-level disk image or so-called Bare Metal backups, are byte-level copies of a full partition or even a complete logical or physical disk. Some utilities will only include used sectors in the copy, thus reducing the size and speed of the backup and restore operations, but this is not always the case. When restoring such a backup, some sort of media, such as a live CD, is required in order to boot up the software to restore the image.

In general, there are two types of backups: low-level image backups, and file-level backups.

Partition resizing may be required ifyou need more space. To get a quick overview of your disk space usage, use the df command. There is also a disk usage (du) command that summarizes file and directory space. Refer to the manual pages for details.

Ifyou must resize a disk partition, the procedures are fairly straightforward but there are some considerations.

There is always a risk in modifying your partition layout. Make sure you have current backups prior to modifying the layout.

Maintenance involves running the Filesystem Check program (FSCK). Ifthe system is rebooted frequently, as is the case with laptops or workstations, or the partition is unmounted and mounted frequently, this will normally happen automatically. EXT3 and EXT4 filesystems default to every 39 mounts when originally created unless otherwise requested. This may be changed using the tune2fs utility which can also set a time-dependent check interval instead of mount count dependent.

Although modern journaling filesystems are quite resilient, they will, on occasion, suffer an error in the underlying infrastructure. The reasons are many and include power fluctuations, hardware failures, and certain types of kernel failures. While the last is extremely rare in Debian stable releases, it does happen, especially ifthirdparty kernel modules that are not part of Debian are installed or ifthe kernel has been modified locally for some reason.

There are two types of filesystem maintenance: partition and content maintenance. The former includes periodic checking of the filesystem's underlying structure and metadata, modifying the partition layout, and low-level backups. The latter involves monitoring and controlling the space used by files as well as file backup and recovery.

Network Manager is automatically installed with the GNOME Window Manager. It is especially useful in a laptop environment. For servers, the interfaces file is probably the best and most flexible option. Of course, ifyou require certain features available only in one or the other, use whatever provides them, combining the two techniques if necessary.

It is possible to combine both the interfaces file and Network Manager methods of network configuration, with each responsible for a portion of the configuration. This technique might be used when certain features are required that only one of the methods support. For example, Network Manager doesn't handle network bridging, and the interfaces file generally can't be used to configure VPN connections. If you needed both, you would set up bridging using the interfaces file and configure your VPN connection using Network Manager.

As flexible as the /etc/network/interfaces configuration is, many administrators prefer a more graphical interface to network configuration that may be used in a more dynamic network environment. Network Manager is most often used to manage wireless connections. It consists of a background process that does the actual connection management and has both a command line and a graphical utility that allows you to configure and control the managed connections.

This is the traditional method for setting up networking on a Debian system. It involves a series of files in fete/network. RPM-based systems such as RedHat Fedora and SuSE Linux use a different layout in /ete/syseonfig/network that is managed by their own utilities.