Talk:Comparison of file systems

Solaris does not support Lustre

Solaris doesn't support Lustre and incorrectly has a Yes box. See Sun's own page or Wikipedia's page. Aolcarton (talk) 17:59, 22 July 2008 (UTC)

NTFS Limits

The Limits section on NTFS states "Allowable characters in directory entries" are "Any Unicode except NUL, /". I believe this is incorrect. As stated in the Microsoft Naming a File page (http://msdn.microsoft.com/en-us/library/aa365247(VS.85).aspx), it clearly states

That almost any character is supported, except for the following:

• The following reserved characters are not allowed:

     < > : " / \ | ? *

• Characters whose integer representations are in the range from zero through 31 are not allowed.

• Any other character that the target file system does not allow.

We discovered this limitation while backing up files from an HFS+ file system to an NTFS 6.0 file system. The HFS+ system had a carriage return (decimal value 13) embedded in the file name.

--Jamercee (talk) 20:56, 17 August 2008 (UTC)

The wikipedia article on NTFS states that "Allowed characters in filenames" in "Posix namespace" is "any UTF-16 code unit (case sensitive) except U+0000 (NUL) and / (slash)" and we are here to compare Filesystem so we must not care of Win32 limitations.

-- 14:18, 29 September 2008 (UTC) —Preceding unsigned comment added by 82.67.232.57 (talk)

I don't think I was clear in my original assertion. While copying files from an HFS+ filesystem to an NTFS filesystem we discovered that carriage return characters were NOT allowed while writting to the NTFS file system. Clearly Carriage-Return characters should have fallen within the range "Any Unicode except NUL, /". It would seem the limitation section should be expanded to encompass the true list of liminations, no?

Jamercee (talk) 20:05, 30 March 2010 (UTC)

Looks like youre confusing what your OS or software app allows with what NTFS allows 82.31.207.100 (talk) 23:25, 20 April 2010 (UTC)

Another limits that seems to be wrong (in contrast to page on ntfs and info on ntfs.com): max. filename length is 255 UTF16 code-points, not 226. Is this a limit yhat evolved over time in different NTFS versions? 82.247.156.143 (talk) 08:36, 6 July 2010 (UTC)

Also just mentioning in passing that Windows XP (presumably NT also) imposes a limit of 259 characters on the full path name but I'm not sure if that is a limitation imposed by NTFS or not.150.101.105.182 (talk) 04:24, 2 September 2010 (UTC)

UFS2 and Block Journaling Support

Please provide reference for UFS2's support of block journaling. I cannot find one.

Moniker117 (talk) 22:19, 28 September 2008 (UTC)

I've been looking around and here's some updates:

• Solaris has support for "logging" using UFS. They introduced it in version 7 of Solaris. This is consistent with what the UFS article in wikipedia says regarding UFS and journaling. This type of journaling is, however, meta-data journaling. Below is a link that confirms the existance of such functionality:

http://docs.sun.com/app/docs/doc/817-5093/fsoverview-43?l=en&a=view&q=ufs+logging

• FreeBSD implements a form of what their documentation calls "block level" journaling through GEOM. This appears to be a feature that is available with UFS or UFS2. Below is a link describing the functionality:

http://www.freebsd.org/doc/en/books/handbook/geom-gjournal.html

• OpenBSD does not implement any form of journaling. See below for link:

http://www.openbsd.org/faq/faq8.html#Journaling

• HP-UX appears to use HFS which is an implementation of UFS and they have a separate file system for journaling support from Veritas. See link below:

http://docs.hp.com/en/B2355-90950/ch02s05.html

I do not doubt that I am missing more operating systems. However, based on the above list, Solaris, FreeBSD, OpenBSD and HP-UX appear to use UFS, but only FreeBSD has data level journaling support. I did not expect one file system to have such variation on one particular feature. It seems fair to me that it should read "No" for both "block journaling" and "meta-data only journaling" under both UFS and UFS2 while having a comment to indicate that certain operating systems implement different levels of journaling support. Any thoughts?

Moniker117 (talk) 04:09, 1 October 2008 (UTC)

Correction on FreeBSD, the GEOM implementation of journaling appears to be filesystem independent. Therefore, it is not a UFS or UFS2 feature.

Moniker117 (talk) 14:36, 1 October 2008 (UTC)

Correction: FreeBSD's gjournal(4) requires filesystem support (transactions) in order to provide the safety guarantees for which journaling is desired; this is implemented in UFS2. (UFS1 is not distinct from UFS2 in this sense: it is the same code, just a different on-disk format. So UFS1 "supports" journaling by default.) 121a0012 (talk) 03:06, 2 October 2008 (UTC)

NetBSD offers journaling on FFSv2 (UFS2) in recent kernels compiled with options WAPBL; mount FFSv2 volumes with the 'log' option to use this feature. —Preceding unsigned comment added by 84.83.37.40 (talk) 03:19, 6 November 2008 (UTC)

Guys, journalling is a feature of filesystem _implementation_, while UFS has many of them. Solaris UFS has journalling. Other UFS implementations don't, except for FreeBSD and NetBSD ones, which seem to be done independently to each other. So, it is unclear whether we can say that UFS implements journalling.

However, UFS2 tends to refer to the current FreeBSD implementation of UFS, which definitely has journalling. Trasz (talk) 12:29, 3 January 2009 (UTC)

Incidentally, the UFS logging in Solaris starts a long time before Solaris 7. In it's original incarnation, it required Disksuite and the logging was on to separate logging devices called trans meta logging. By Solaris 7, the log devices became invisible log files within the filesystem, and it was being bundled for free with the base OS, so it started being more widely known. 81.187.162.109 (talk) 06:39, 17 May 2009 (UTC)

HFS+ Online Shrink/Grow

Online shrink/grow for HFS+ are currently listed as "unknown". The Boot Camp Assistant allows shrinking (when you create a Windows partition) and growing (when you delete one) of the running system's HFS+ partition. I don't know whether this is implemented in the FS driver or if it's a hack implemented somehow else... 24.60.192.190 (talk) 23:12, 23 January 2009 (UTC)

Mistakes about ReiserFS?

The two tables for Metadata and Features, ReiserFS (which I assume is of the version 3) has none of the discussed properties ('No' for every single item). While I am no expert in file systems and ReiserFS in specific, this seems to be contradicting the page of ReiserFS, which states that one of the most publicised features of ReiserFS is "Metadata-only journalling". This suggests ReiserFS should have the minimal metadata for the purpose of system journalling. Besides, the table Features should otherwise have at least the Metadata journalling set to 'Yes' for ReiserFS. I have also checked earlier versions of this page (beginning of this year), and found that the tables were indicating many different properties for ReiserFS.

Obviously, vandalism has happened to this page recently. The maintainer of this page please restore the page to the proper state. It is much appreciated. 125.253.12.53 (talk) 14:34, 22 February 2009 (UTC)

The page about Extended attribute does state that ReiserFS, at least in recent versions, does feature xattr / metadata support! —Preceding unsigned comment added by Zuckerberg (talk • contribs) 13:17, 2 September 2010 (UTC)

http://linux.die.net/man/8/mount states that ACLs are supported in reiserfs. –84.169.112.96 (talk) 22:57, 26 January 2012 (UTC)

There is also the text “Full block journaling for ReiserFS was not added to Linux 2.6.8 for obvious reasons.” To me, the reasons are not obvious. That should be expanded upon, or some reference given. –84.169.112.96 (talk) 23:04, 26 January 2012 (UTC)

Include WinFS?

I was just reading about WinFS on it's own WikiPedia page, and was wondering how it compared to all these other file systems. It's not here. Oh well. I think it would be nice to have here. 71.174.4.229 (talk) 20:41, 7 June 2009 (UTC)

NTFS for windows 98 driver?

The link given is broken, does anyone have a backup for the driver that allows NTFS to be used with Windows 95/98? I could really use it. Coolgamer (talk) 03:43, 12 August 2009 (UTC)

NTFS 6.0

There does not exist any NTFS 6.0 ! There are only system extentions of Windows NT 6.0 (Vista/2008) but inside the specifications of the current NTFS 3.1

Deduplication

I've added a new column to the features table to cover deduplication. I've filled in what I know of existing or being in development, but this leaves a lot of unknown entries. I suspect that all of the unknown's are really no but I don't have the knowledge to say for sure. Darrenmoffat (talk) 11:38, 24 September 2009 (UTC)

Suggested Updates/Todos

I've Added/Updated Tables 1 and 2 for exFAT and TexFAT. But these 2 FS types should be added to tables:

• 3 Metadata
• 4 Features
• 5 Allocation and layout policies
• 6 OS support

Also Table 6 OS Support Needs Windows XP, Vista and Windows 7 break out (maybe in the same column?) Frankk74 (talk) 06:52, 14 October 2009 (UTC)

Sorting across the tables should be refined or made more consistent? Any thoughts?

Info about XP, Vista, and Win7 would be nice... It has been many since NT stopped being supported. 72.251.91.186 (talk) 02:43, 22 October 2009 (UTC)

Windows NT refers to the entire family of NT OSes; Microsoft decided to call NT 5.0 "Windows 2000", and all subsequent Windows NT OSes have had names that don't start with "Windows NT", such as "Windows XP", "Windows Vista", "Windows 7", "Windows Server 2003", "Windows Server 2008", etc.. Guy Harris (talk) 19:51, 17 January 2010 (UTC)

File Creation Time Stamps

Why there is "NO" for ReiserFS & Ext? for File Creation Time Stamps? I feel that this article is worthless since it contains obviously erroneous information. Might someone fix that or delete the article? --82.113.121.154 (talk) 21:00, 28 November 2009 (UTC)

My understanding is that these do not give you file creation time stamps. Instead you get the last inode update timestamp. Initially this corresponds to the creation time, but later changes (such as to file metadata) may change that timestamp, without modifying the underlying file data. —Preceding unsigned comment added by 216.105.130.254 (talk) 05:33, 28 July 2010 (UTC)

Market share

It would be interesting to have some comparison of market share or some other usage statistic, either here or on file system. -- Beland (talk) 14:29, 1 December 2009 (UTC)

It might, indeed. However, as file systems are hardly ‘products’ in the original sense (more like an abstract design), then the concept of ‘market’ is difficult to apply. This would be like having ‘market share’ for natural languages, as such. How would such data be collected, anyway? You've then got statistical analysis problems; for example: how should someone using multiple file systems be counted? They're not mutually exclusive, via partitioning. — Lee Carré (talk) 13:54, 27 December 2010 (UTC)

OS support

I feel that this table would be much more useful if it did not list any filesystems until they are supported by more than one OS. After all, while long list of special purpose linux filesystems is interesting, it seems like it perhaps defeats the purpose of this table? Why not focus on Cross-OS support, perhaps even labeling it such instead? —Preceding unsigned comment added by 66.162.99.237 (talk) 19:15, 29 December 2009 (UTC)

Would it make sense to add more mobile OSs? Android? — Preceding unsigned comment added by 50.157.95.208 (talk) 09:43, 17 April 2014 (UTC)

UFS2 limits

According to http://www.freebsd.org/projects/bigdisk/index.html, UFS2 file and volume limit is 2^73, not a "Yobibyte". --Eike sauer (talk) 08:56, 30 March 2010 (UTC)

Units for bytes

I just noticed this article uses lot of IEC prefixes such as EiB but WP:MOSNUM states the IEC prefixes are not to be used except in a few conditions that are not met by this article. I think changing the article to use familiar prefixes would be an improvement. 217.213.60.238 (talk) 18:47, 30 March 2010 (UTC)

It looks like the relevant bit of the MoS is specifically WP:COMPUNITS.

Currently the "Limits" section uses KB, MB, GB, TB, PB, EB, ZB, and YB. Some entries define them more precisely (usually x * 1024^n bytes), but many don't. In general these limits are derived from binary values, so perhaps there should be a note covering the whole table to say this. My opinion is that KB is confusing (though probably correct), MB and GB are definitely ambiguous, and TB and so on are actually incorrect, at least according to the JEDEC prefixes listed in Template:Bit and byte prefixes.

For example I was looking for information on UDF. The table says the maximum file size is 16 EB, and I think this is derived from 64-bit file sizes: 2^64 = 16 EiB. The table says "unknown" for UDF's maximum volume size, though I think I saw elsewhere it is 2^32 * (block size), which would be 2 TiB = 2^(32 + 9) for 512 B block hard disks and 8 TiB = 2^(32 + 11) for 2048 B block optical discs.

Personally I think TiB is generally more clear, and in this particular situation makes it clear that it's a different unit to the decimal TB commonly used for hard disks. For example it might avoid suggesting that a 2 TiB file system and a 2 TB hard disk are exactly the same size. But maybe I'm just being too technical, and there's a sentence in the MoS that says don't use the IEC units anyway.

Vadmium (talk) 02:32, 17 December 2010 (UTC)

As per the MOS I have changed the article to reflect the current consensus. HumphreyW (talk) 12:43, 15 December 2011 (UTC)

V6FS Max Size

This may sound random, but Wikipedia led me astray on my home work and I should try to prevent it for others. The given max size in: "The actual maximum was 8,847,360 bytes, with 7 singly-indirect blocks and 1 doubly-indirect block; PWB/UNIX 1.0's variant had 8 singly-indirect blocks, making the maximum 524,288 bytes or half a MiB." is incorrect. According to the Version 6 Manual, http://wwwlehre.dhbw-stuttgart.de/~helbig/os/v6/doc/V/fs.html, the max size is 32, but cannot be larger than 16 bue to only storing 24-bits of filesize info in each inode rather than 25. The 8,847,360 number obtained above was the result of calculating it with 4 byte addresses, which is obviously incorrect given the definition in the manual. Vkgfx (talk) 06:00, 7 April 2010 (UTC)

CoLinux

CoLinux is a port of the linux kernel. It allows running Linux natively under Windows. Therefore it is possible to use XFS, ReiserFS and ext3 in Windows as described here. Maybe this is mentionable? --Olytibar (talk) 05:42, 30 June 2010 (UTC)

Windows already has the ability to use XFS, ext3, etc. if by "use" you mean "connect to a linux box on the network that is running Samba" CoLinux makes it possible for that Linux box to be the same box that is running Windows, but it is still accessing a network share. We don't count as being supported filesystems that are accessible by connecting to an OS running on a virtual machine, so we shouldn't count them under CoLinux.

It might be worthwhile mentioning in the article that support for non-native partitions is often available through these methods. That is very useful information for someone who doesn't know the trick. Guy Macon 13:24, 19 September 2010 (UTC)

Why Isn't There More Information On Amiga OS?!

I am going to add more information on Amiga OS. It has information on the first table but none on the others. If anybody has objections to this, post them here and soon. In-Correct (talk) 00:05, 12 July 2010 (UTC)

GEORGE 2 & GEORGE 3

I notice that "George 2" appears as a file system, though without any reference or link. I don't know anything about GEORGE 2 but I did use GEORGE 3 and so I know that its filestore was very significant, having automatic volume management with backups, versioning etc. Were these the same filesystem or not? The GEORGE 3 one should certainly appear in the table, IMHO.

George 1 and 2 were really just batch job dispatch systems that sat on top of a standard ICL executive. You could use them or not, they were just slightly more privileged standard processes. George 3 was a complete operating system that took over the entire machine. One could only run George 3 on the larger "West Gorton" (and later "Stevenage") ICL machines that had extended branch mode addressing. 82.68.205.1 (talk) 18:16, 13 December 2013 (UTC)

There is a wikipedia entry about GEORGE - GEORGE_(operating_system) - that refers to online GEORGE 3 documentation including a description of the filestore http://www.icl1900.co.uk/g3/filestor.html 131.111.85.79 (talk) 09:40, 1 September 2010 (UTC)

Modern System Only Option

Many people coming to the page are only interested in comparing current Files Systems to decide which to use. However, because all of the comparison tables are multiple screens long and compare every file system that has existed, they find the page to be mostly useless. We need a way to show only current information for those who want it, in order to increase utility. A method for allowing the viewer to sort information and suppress what they don't need would also be good.

This is a general comment applicable to all comparison articles. —Preceding unsigned comment added by 136.142.206.28 (talk) 22:40, 15 October 2010 (UTC)

Original Operating System

The purpose of the field 'Original Operating System' is not clear. I would assume that it applies to the Operating System/s the Filesystem first appeared in. However, the field does not currently appear to reflect this. I have removed some anachronisms ie Windows pre NT (Windows v1 - 3.1 were not operating systems), and Mac OS X pre 1999, Linux pre 1990. There appear to be some other issues, eg Joilet support was not originally present in Mac OS and required an extension to be added, ISO9660 was not included in the Amiga OS until OS3.1 (released about 1992) but was available as a third party add on), XFS was originally IRIX only and then later ported to Linux (and by this logic, virtually all the FS could have Linux listed), and no doubt more. The solution may be to have two fields, one called Original Operating System, and another listing OSes which support the filesystems. 138.25.11.181 (talk) 03:04, 16 October 2010 (UTC)

Maximum file size and Maximum volume size format

Why aren't the values in these two columns in the scientific notation? This way the sorting by each of the columns would work correctly (now it doesn't).

512upload (talk) 22:38, 18 November 2010 (UTC)

-

Still undone - very annoying!!!

-

I have fixed this on 20 September 2015 with edit 681972851 - 162.222.246.77 (talk) 18:40, 20 September 2015 (UTC)

iOS (Apple)

What is the maximum file size for Apple iOS, which is used in the iPhone and iPad? I've been trying to find this official fact. • Sbmeirow • Talk • 22:02, 23 December 2010 (UTC)

iOS uses HFSX, which is HFS+ with a few minor tweaks, none of which affect the maximum file size. Foxyshadis^(talk) 09:26, 10 December 2011 (UTC)

Request for extra information about metadata space efficiency (percentage use of drive capacity)

I would, personally, like to see comparison data between the efficiency of differing file systems, particularly in the context of what percentage of the absolute total capacity is needed for file system metadata in order for it to represent the file system itself. For example, a less space-efficient design would use a larger percentage just to store metadata, rather than actual files, and vice versa. I realise that there are often more important factors than pure efficiency; such as discoverability for diagnostics, scalability, reliability, redundancy, et al. Notes on original design goals would be useful, too, if known, such as design for file storage, database, streaming media, sequential vs random access, et al. — Lee Carré (talk) 14:01, 27 December 2010 (UTC)

Most modern filesystems do not use a fixed reservation for filesystem metadata; the number you ask for will depend on the size, structure, and number of files stored, and in many cases also on the modification history, presence of snapshots, use of journaling, stride length, and size of the underlying disk sectors. So what you ask for really cannot be defined rigorously without a precise specification of the contents of the filesystem (and even there, the results would likely not be realistic). For filesystems with integrated volume management, like ZFS, it would also depend on the configuration of the underlying storage pool. 121a0012 (talk) 22:24, 28 December 2010 (UTC)

Feb-2009 vandalism needs stripping out

I was wondering about the {{Contradict-other|File Allocation Table|date=February 2010}} hatnote as there was no talk thread. I tracked the addition of the hatnote down to this massive edit on 16 Feb 2009. A couple of minutes after that edit is this small one by the same user. I took a look at Special:Contributions/Gzpguest and am quite concerned about that user's edit's to this article as he/she was blocked for edits to other articles and some of the user's contribution to this article was clearly an attempt to vandalize it.

I don't know if it was WP:AGF at work or the edits were overlooked. Someone corrected Gzpguest's change of ReiserFS to MurderFS but an edit battle of sorts started with people attempting to re-insert MurderFS wording and it looks like most of the Gzpguest contribution snuck through including the hat note that got my attention today.

I don't have time to do a blow-by-blow check of what Gzpguest modified in those two edits against the current article but believe we need to revert all information that this user added/removed to the article. Hopefully someone's got the time for that thankless task. I'll start by removing the hat note. --Marc Kupper|talk 07:34, 31 December 2010 (UTC)

Allowed characters in NTFS file names

The articles says all Unicode character except NUL and \ / : * ? " < > | are allowed, but in Linux NTFS files can contain any Unicode character except NUL and /. —Preceding unsigned comment added by 193.150.222.25 (talk) 13:49, 20 January 2011 (UTC)

IlesfayFS?

Is it mentioned outside its inventors' site and this page? Notability? 195.98.165.2 (talk) 20:42, 8 February 2011 (UTC)

Remove HPUX

Besides being an essentially dead OS, the column is currently useless, which all unknowns except for one single Yes. If no one objects or fills it in, I'll remove it until someone comes in with better data. Foxyshadis^(talk) 09:27, 10 December 2011 (UTC)

ICT/ICL 1900 file systems

A previous commenter has mentioned the inappropriate inclusion of George 2, which was in fact an operating system. The file system underlying George 2 (and all ICL 1900 executives/operating systems prior to George 3/4) was originally BDAS (Basic Direct Access Standards) and later UDAS (Unified Direct Access Standards). UDAS was noteworthy in providing a standard which meant that applications did not need recompilation, whatever type of direct access device they were accessing, anything from a small Twin EDS (about 1.5 megabytes, as I recall) to a large fixed disk. I am unclear to what extent the George 3 filestore was founded on UDAS, but on balance I think it was. 86.139.4.232 (talk) 20:39, 1 January 2012 (UTC)

ExFAT correction...

Why ExFAT's "year introduced" column has two dates? 2006 and 2009? it makes no sense. It was introduced in 2006 Cainamarques (talk) 02:35, 23 August 2012 (UTC)

Merger proposal

A merger proposal was made by Ruud Koot in January to merge List of file systems into this article but no discussion was started, so in before merging by silence...

Oppose - The differentiation between list and comparison works, they have different scopes so there is no overlap and also the resulting article would be too long Cainamarques (talk) 05:00, 25 August 2012 (UTC)

handling small files

please someone add how well the different file systems are at handling many many small files. i understand that reiserfs is good at this, and jfs is also alright, but that most file systems are not. please add this information. 41.204.77.67 (talk) 09:04, 18 October 2012 (UTC)

Handing of small files

Two questions that I can't find the answer to using this page:
1. What is the performance of handling high amounts of small files (up to a few dozen sector)? For example, FATxx and ReiserFS are very fast and journaling file systems (eg. NTFS) can be extremely slow.
2. How many files can be stored in one directory? For example, the only reason I'm not using FAT32 anymore is because when you put more than about 30000 files in a directory, it says disk full, while in fact only the directory is full. Exact number varies with length of filenames. --Zom-B (talk) 02:17, 11 November 2012 (UTC)

undelete

in praxis it is very important how good accidentally remarked files can be restored. for example fat, reiser3.6, ext2 files can be easier restored - ext3 is cruel 79.203.151.23 (talk) 22:46, 8 December 2012 (UTC)

QLFS?

One more for the pot? The disc file system of the Sinclair QL launched in 1984. [1] — Preceding unsigned comment added by 66.81.120.218 (talk) 09:43, 12 December 2012 (UTC)

HDFS

What about less POSIX file systems? — Preceding unsigned comment added by 192.115.180.11 (talk) 10:27, 26 May 2013 (UTC)

Date range

I think it would be of interest to have a column "Date range". BuSchu (talk) 09:13, 17 October 2013 (UTC)

Separation of Resize feature column (in feature section)

Does it make sense to do the effort to separate the column for resize feature in one for online and one for offline resizing. Currently, the overview is rather poor as a statement like "Online (cannot be shrunk)" does not point out whether the shrinking is not possible online (but offline it is) or not possible in general. Some information is only usable if one reads the citation source, e.g. one might think that ext4 is online shrinkable after having a look on the table, while it might make the information in the footnote more easily accessible. Krichter1 (talk) 20:11, 27 January 2014 (UTC)

UFS Grow in FreeBSD

The ability to grow a UFS File system was added in FreeBSD 10 according to the Developers and many other sites and tutorials

[[2]]

[[3]] 89.207.120.69 (talk) 10:25, 21 February 2014 (UTC)

Windows Vista, Windows 7, Windows 8 not represented for "Average Joe" readers who don't know if Windows NT is the same or not

A major current OS is not represented in the supported OS section: Windows 8. Whatever its lineage, Win 8 may or may not have support for file systems that could differ from Win NT and Win 9x. Yet Win NT and Win 9x are the only "Windows" columns in the "Supported operating systems" section. For a non-power or non-historically-knowledgeable current Windows user, this supported OS section seems out of date. 169.234.72.254 (talk) 19:49, 18 April 2014 (UTC)

"Linux has a pathname limit of 4,096."

... of 4,096 what? UTF-8 coded Characters? Or Bytes? --91.15.18.34 (talk) 06:04, 24 January 2015 (UTC)

My math teacher would have a fit if she saw this. "ALWAYS use units, even on Wikipeia" 74.243.139.75 (talk) 18:04, 11 August 2015 (UTC)

ext filesystem limitations

The massive edit on 24 July 2015 (-42,930 characters) removed a lot of information and reformatted pretty much everything. All the ext filesystems had their "Allowable characters in directory entries" changed from "Any byte except NUL and /" to "Any byte except NUL". I believe this is in error. See http://stackoverflow.com/questions/9847288/is-it-possible-to-use-in-a-filename and the function "link_path_walk" in the source.

Thoughts or arguments? I propose the change be reverted. — Preceding unsigned comment added by 162.222.246.77 (talk) 16:14, 20 September 2015 (UTC)

UDF sparse file support

It surprised me that UDF was listed as not supporting sparse files. I have had success on FreeBSD and OS X with this in the past, in fact very long ago. The simplest way to do sparse files is with short_ad (Short Allocation Descriptor) marked 2 (extent not recorded and not allocated). Since two bits are needed for the type you have 30 bits left for the size. Assuming 512 block size, this permits holes of up to 1GB. Possibly linux or other OSes does not implement sparse file support or ls does not report it correctly, but at least when I tried it it worked in the naive manner of seeking to create the holes. Also this will work in any UDF version and any compliant implementation will return zeros on reading it.