Debian

There are various fonnats supported for clustered systems, including AFS and GFS2. In general, they are not used for the basic system files required for booting, but are better suited for shared data. It is possible to set up such systems for booting, but this is beyond the scope of this discussion. Ifyou are interested, there are a number of publications available on Linux clustering. A good starting point might be the Wikipedia article on clustered filesystems at http:/len. wikipedia.org/wikil Clustered_file_system.

B-Tree File System (Btrfs) is the next Linux filesystem format. It focuses on faulttolerance, repair, and easy administration, with the ability to scale up to larger storage configurations. ext-based systems can be easily converted to Btrfs. For the moment, Btrfs is still under heavy development, although only forward-compatible fonnat changes are anticipated. Debian 7 does allow it to be used, but it is not yet recommended for production systems.

Reiser File System (ReiserFS) was intended to supplant ext3 as the filesystem of choice for Linux, offering improved performance. At one point, ReiserFS version 3 was the default format choice for SuSE Linux. Version 4 was released, but development waned when the company went out of business, and SuSE eventually decided to go back to ext3 as its default.

XFS is another alternative, developed by Silicon Graphics in 1993. It is a high-speed JFS, with emphasis on parallel input/output (I/O). The NASA Advanced Supercomputing Division uses this format on their 300+ terabyte Altix storage servers. Metadata operations are somewhat slower than other formats, although this was improved somewhat with the changes made by Red Hat. This is a good choice where metadata changes very little (such as few file or directory creation, move, or delete operations) and I/O performance is of utmost importance.

Developed by IBM for its Unix-like AIX operating system, and offered as an alternative to the ext and ext2 filesystems via release under the GPL, Joumaled File System OFS) is one of the alternatives to the current ext4. It uses fewer resources, while remaining quite stable and resilient. It includes many features of Btrfs, and is a good choice when CPU power is limited, or with database systems that require synchronous writes to survive hardware failures.

The ext filesystem was originally developed to overcome the limitations of the MINIX filesystem..

MINIX was linus Torvalds' inspiration for linux.

The second extended filesystem (ext2) improved upon it, while the third extended filesystem (ext3) added joumaling, as well as performance improvements. The fourth extended filesystem (exl4) added additional features and performance improvements.

• The ability to disable joumaling is one reason ext2 was sometimes used over ext3 for flash drives in order to reduce the write cycles.

Selecting a filesystem format is the next major choice before installing Debian. The supported formats that are appropriate for a Linux installation include ext2, ext3, ext4, JFS, XFS, ReiserFS, and Btrfs. The first three are actually progressive versions of the extended filesystem (ext) developed specifically for Linux.

The UEFI is a recent development by Intel and Microsoft that supports what is called Secure Boot, which requires all the loaded firmware to be signed or it won't be loaded. This is a problem for Linux, since the keys required for signing must, under the current GPL, be made public. This, of course, defeats the purpose. There are several workarounds, including some being used by Red Hat, SuSE, and Ubuntu, which are being discussed by the Debian developers and will probably be included in an update at some future point.

BIOS is the traditional boot method, and is well-supported by Debian. There are several choices for the placement of the boot code. Common practice is for it to be placed in the MBR at the beginning of the boot disk. However, if there are multiple operating systems already installed (especially Microsoft Windows), this replaces the installed bootloader with the one common to Linux. This is generally not a problem, since the installation and update process searches for other operating systems and includes the ability to boot them as an alternative in the boot menu.

Up until the late 1990s, the Basic Input/Output System, or BIOS, was the way all Intel-based systems were booted. Its disk partitioning information was held in a Master Boot Record (MBR) with additional code in the first sector of each bootable partition. With the advent of the Microsoft-sponsored Secure Boot feature, and its associated boot mechanism known as the Universal Extensible Firmware Interface (UEFI), there is a new partitioning layout and additional considerations.