file system in linux

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file system (ext2, ext3, reiserfs etc)
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Linux supports several types of filesystems. As of this writing the most important ones are:
minix-The oldest, presumed to be the most reliable, but quite limited in features (some time stamps are missing,
at most 30 character filenames) and restricted in capabilities (at most 64 MB per filesystem).
xia-A modified version of the minix filesystem that lifts the limits on the filenames and filesystem sizes, but
does not otherwise introduce new features. It is not very popular, but is reported to work very well.
ext3-The ext3 filesystem has all the features of the ext2 filesystem. The difference is, journaling has been
added. This improves performance and recovery time in case of a system crash. This has become more popular than
ext2.
ext2-The most featureful of the native Linux filesystems. It is designed to be easily upwards compatible, so that
new versions of the filesystem code do not require re-making the existing filesystems.
ext-An older version of ext2 that wasn't upwards compatible. It is hardly ever used in new installations any more,
and most people have converted to ext2.
reiserfs-A more robust filesystem. Journaling is used which makes data loss less likely. Journaling is a mechanism
whereby a record is kept of transaction which are to be performed, or which have been performed. This allows the
filesystem to reconstruct itself fairly easily after damage caused by, for example, improper shutdowns.
jfs-JFS is a journaled filesystem designed by IBM to to work in high performance environments>
xfs-XFS was originally designed by Silicon Graphics to work as a 64-bit journaled filesystem. XFS was also
designed to maintain high performance with large files and filesystems.
In addition, support for several foreign filesystems exists, to make it easier to exchange files with other
operating systems. These foreign filesystems work just like native ones, except that they may be lacking in some
usual UNIX features, or have curious limitations, or other oddities.
msdos-Compatibility with MS-DOS (and OS/2 and Windows NT) FAT filesystems.
umsdos-Extends the msdos filesystem driver under Linux to get long filenames, owners, permissions, links, and
device files. This allows a normal msdos filesystem to be used as if it were a Linux one, thus removing the need
for a separate partition for Linux.
vfat-This is an extension of the FAT filesystem known as FAT32. It supports larger disk sizes than FAT. Most MS
Windows disks are vfat.
iso9660-The standard CD-ROM filesystem; the popular Rock Ridge extension to the CD-ROM standard that allows longer
file names is supported automatically.
nfs-A networked filesystem that allows sharing a filesystem between many computers to allow easy access to the
files from all of them.
smbfs-A networks filesystem which allows sharing of a filesystem with an MS Windows computer. It is compatible
with the Windows file sharing protocols.
hpfs-The OS/2 filesystem.
sysv-SystemV/386, Coherent, and Xenix filesystems.

The ext3 File System
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The default �le system is the journaling ext3 �le system.
Features of ext3
The ext3 �le system is essentially an enhanced version of the ext2 �le system. These improvements
provide the following advantages:
Availability
After an unexpected power failure or system crash (also called an unclean system shutdown),
each mounted ext2 �le system on the machine must be checked for consistency by the e2fsck
program. This is a time-consuming process that can delay system boot time signi�cantly, espe-
cially with large volumes containing a large number of �les. During this time, any data on the
volumes is unreachable.
The journaling provided by the ext3 �le system means that this sort of �le system check is no
longer necessary after an unclean system shutdown. The only time a consistency check occurs
using ext3 is in certain rare hardware failure cases, such as hard drive failures. The time to
recover an ext3 �le system after an unclean system shutdown does not depend on the size of the
�le system or the number of �les; rather, it depends on the size of the journal used to maintain
consistency. The default journal size takes about a second to recover, depending on the speed of
the hardware.
Data Integrity
The ext3 �le system provides stronger data integrity in the event that an unclean system shutdown
occurs. The ext3 �le system allows you to choose the type and level of protection that your data
receives. By default, the ext3 volumes are con�gured to keep a high level of data consistency
with regard to the state of the �le system.
Speed
Despite writing some data more than once, ext3 has a higher throughput in most cases than
ext2 because ext3’s journaling optimizes hard drive head motion. You can choose from three
journaling modes to optimize speed, but doing so means trade-offs in regards to data integrity.
Easy Transition
It is easy to migrate from ext2 to ext3 and gain the bene�ts of a robust journaling �le system
without reformatting. Refer to Section 6.3 Converting to an ext3 File System for more on how to
perform this task.
The following sections walk you through the steps for creating and tuning ext3 partitions.
For ext2 partitions, skip the partitioning and formating sections below and go directly to
Section 6 Converting to an ext3 File System.

[vaengaivenkat]

Thanks for sharing................

[paulkingston]

thanks now i know what works an what not

[perdhanahost]

Nice share! many thanks for that

[Deltahost]

Article a little bit outdated. Now come Ext4 and ZFS