LinuxConfig -

Linux System Administration

July 31, 2009
By Pierre Vignéras More stories by this author:

Abstract:

As you may probably know, Linux supports various filesystems such as ext2, ext3, ext4, xfs, reiserfs, jfs among others. Few users really consider this part of a system, selecting default options of their distribution's installer. In this article, I will give some reasons for a better consideration of the file-system and of its layout. I will suggest a top-bottom process for the design of a ``smart'' layout that remains as stable as possible over time for a given computer usage.

Introduction

The first question that you may ask is why are there so many file-systems, and what are their differences if any? To make it short (see wikipedia for details):

ext2: it is THE Linux fs, I mean, the one that was specifically designed for linux (influenced by ext and Berkeley FFS). Pro: fast; Cons: not journalized (long fsck).
ext3: the natural ext2 extension. Pro: compatible with ext2, journalized; Cons: slower than ext2, as many competitors, obsolete today.
ext4: the last extension of the ext family. Pro: ascending-compatibility with ext3, big size; good read performance; cons: a bit too recent to know?
jfs: IBM AIX FS ported to Linux. Pro: mature, fast, light and reliable, big size; Cons: still developed?
xfs: SGI IRIX FS ported to Linux. Pro: very mature and reliable, good average performance, big size, many tools (such as a defragmenter); Cons: none as far as I know.
reiserfs: alternative to ext2/3 file-system on linux. Pro: fast for small files; Cons: still developed?

There are other file-systems, in particular new ones such as btrfs, zfs and nilfs2 that may sound very interesting too. We will deal with them later on in this article (see 5

So now the question is: which file-system is the most suitable for your particular situation? The answer is not simple. But if you don't really know, if you have any doubt, I would recommend XFS for various reasons:

Network Bits: 16
Network bits available ( x ):10xxxxxx xxxxxxxx hosts hosts this leave us with 14 bits designated to the number of networks. Since there are two possible bits to play with ( 1 or 0 ) the range of network is 2^14 = 16384. We need to subtract broadcast and network ID and the number of networks available is 16382.
RANGE: 10000000 – 10111111 -> 128 -191
Hosts:The number of available hosts can be calculated from a remaining 16 host bits. 2^16 = 65,536 subtract network ID and broadcast adress and this gives us 65,534 hosts available for CLASS B Network.

By default K3b or brasero burning software will refuse burn encrypted dvd. One way to overcome this problem is by using libdvdcss library whish allows K3b or brasero to look at your encrypted DVD within DVD-device as a block device and thus disregarding its encryption. Before running K3b or brasero install libdvdcss library to allow it clone / burn encrypted DVD.

On Debian or Ubuntu libdvdcss installation to allow K3b burn encrypted DVD's:

apt-get install libdvdcss2

If you are using debian and libdvdcss2 is missing make sure that you have www.debian-multimedia.org in your repository. Once done palce encrypted DVD into your DVD-Burner and start copy.