There are a variety of filesystems that can be used on a Linux system, including ext2, ext3, XFS, JFS, Reiser's, NFS, and of course, Linux can deal somewhat with foreign filesystems, like FAT, FAT32, NT, and others I'm not even thinking about (VMS, ???).

I didn't realize it or think about it until today that there is more to consider when choosing a filesystem than speed or reliability -- some of the filesystems might not support features that I consider important. (Thanks to J. Craig Woods for pointing this out in a post on expert@linux-mandrakePLEASENOSPAM.com.)

This is a first attempt at summarizing some of the issues to be considered. It is very much a first draft, and may be factually incorrect at this point (as well as incomplete).

See AboutThesePages.

Contents

Abbreviations and Definitions

Headings in the table:

• FS -- a common abbreviation for the filesystem
• Attribs -- does this filesystem support the LinuxFileAttributes
• Defrag -- does the filesystem require defragging
• Comments

Note: I expect to need to expand this table to deal with other issues -- will do so as they are identified.

Filesystem Summary Table

I've now deleted civileme's "ratings" from the table and included his recent comments on journaling file systems under the next heading.

FS	Attribs	Defrag	Comments
ext	?	yes	obsolete
ext2	yes	no	Linux standard
ext3	yes	no	data/metadata journalling
JFS	yes	yes	metadata journalling
XFS	yes?1	no	metadata journalling
ReiserFS	yes	no	metadata journalling
OpenAFS	?	?	network -- AFS?
NFS	?	no	network
FAT	no	yes	DOS/Windows
FAT32	no	yes	DOS/Windows
NTFS4	?	yes	Windows NT4
NTFS5a	?	yes	Windows 2000
NTFS5b	?	?	Windows XP

Notes:

1. quoting from a 28 Mar 2002 post by Lyvim Xaphir, referring to an IRC chat with an XFS developer: "The other was that he was positive that the chattr command would be unable to set an "i" attribute under XFS. He seemed unsure as to wether there were other unsupported attributes or not."

Resources

• (rhk) Common threads: Advanced filesystem implementor's guide, Part 1: Journalling and ReiserFS; Daniel Robbins; Nov, 2001 -- part of an eight (or more) part series -- haven't read it, but it seems worthwhile -- maybe we need the Reader's Digest version (here on WikiLearn) -- this article includes links to the other articles and additional resources that may be useful --

What's In Store

The purpose of this series is to give you a solid, practical introduction to Linux's various new filesystems, including ReiserFS, XFS, JFS, GFS, ext3 and others. I want to equip you with the necessary practical knowledge you need to actually start using these filesystems. My goal is to help you avoid as many potential pitfalls as possible; this means that we're going to take a careful look at filesystem stability, performance issues (both good and bad), any negative application interactions that you should be aware of, the best kernel/patch combinations, and more. Consider this series an "insider's guide" to these next-generation filesystems.

Civileme's Comments on Journaling Filesystems

civileme is a well respected poster on newbie@linux-mandrakePLEASENOSPAM.com and expert@linux-mandrakePLEASENOSPAM.com, and a Mankrake employee:

XFS supports ACLs (yes Windows ACLs under Samba)

JFS is the fastest I have tested, but I was still able to break it in 8.1 The newer one seems steadier.

ext3 is slow compared to the others, but doesn't break and usually recovers nicely. I have managed to destroy a Reiser partition with unexpected poweroffs, but not (yet) the others.

(This was in a series of recovery tests I am running)

A different quote: "Reiser is maturing nicely, but still doesn't like postfix."

SridharDhanapalan's Comments on Journaling Filesystems

Ext3 is both forwards and backwards compatible with ext2. This means that an ext2 filesystem can be converted into ext3 and vice versa. Ext3 offers a choice of no journalling (making it similar to ext2), metadata journalling and data journalling. The other Linux journalling filesystems do not support data journalling, so ext3 can be seen as the safest Linux filesystem. However, it is also the slowest.

ReiserFS has been optimised for small files, but not at the expense of large file performance. XFS is optimised for larger files.

ReiserFS has had some issues with NFS and RAID configurations when using early versions of the 2.4 kernel. This was fixed in Linux 2.4.7.

JFS is probably the fastest journalling filesystem, but there are some drawbacks. Files take up more space than they would on other filesystems. JFS filesystems require periodic defragmenting; this can be set up as a cron job to run at a low peak usage time.

Contributors

• RandyKramer - 28 Mar 2002
• J. Craig Woods - 28 Mar 2002
• civileme - 28 Mar 2002
• SridharDhanapalan - 29 Mar 2002
• <If you edit this page, add your name here, move this to the next line>

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