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New ReFS file system to debut in Windows 8

Written by Rich Fiscus (Google+) @ 17 Jan 2012 7:09 User comments (13)

New ReFS file system to debut in Windows 8 In Windows 8 Microsoft will be introducing a new file system called ReFS. It borrows a number of features from the NTFS file system which has been available on Windows NT (NT 3.1 - 4, 2000, XP, Vista, 7) computers from 1993 on.
This is not the same as the database driven WinFS file system announced for, and later pulled from Windows Vista. That file system has since been abandoned by Microsoft, with parts of it being used in their database products.

The underlying technology of ReFS features a number of improvements over NTFS. While these changes should be invisible to the average user, the performance and resiliency improvements should be obvious in certain circumstances.

One of the changes is switching from journaling to write-on-allocate for metadata updates. In NTFS, when metadata for a file or folder (name, security permissions, and other information) is altered, those changes are also recorded in a journal in case they need to be rolled back. Normally this is reliable, but data may be corrupted if the drive loses power in the middle of an operation.

The write-on-allocate strategy used in ReFS improves on that by making all metadata changes to a different location (ie copying, rather than overwriting) so the original metadata is left completely intact. If the drive loses power while metadata is being changed, the original will still be available.

You can take that a step further by enabling integrity streams, which is designed for optimum corruption resistance. With this feature enabled, both files and the associated metadata are written to a new location on the disk. The original is maintained in case you need to recover it later.

While integrity streams should be better from a reliability standpoing, it may degrade performance of certain applications. Databases, in particular, may take a performance hit when data is moved around the disc too much. Of course, if your database isn't changed often, this may not be a consideration.

With a feature called integrity streams, the same strategy can be used for modifying the actual file data. In other words, if you edit and save a file, rather than being overwritten a new version of the file will be created. Once it is saved, the new (and updated) copy replaces the original.

ReFS also uses B+ trees for mapping out file and folder names and locations. This essentially removes the NTFS limits on file and folder size and the number of characters in a name. There are still limits, but they are literally thousands of times the size of the biggest consumer hard drives available today.

Drives formatted with the ReFS file system may also use another new feature in Windows 8 called Storage Spaces (also available for NTFS drives). Storage Spaces provides various options for pooling physical discs into a single logical location. This replaces the striping, mirroring, and spanning features from previous Windows versions.

Since a big part of ReFS comes directly from NTFS, the file system API is the same. That means programs which work with the NTFS file system should work exactly the same with ReFS. Actually there will be minor differences, but those are due to features which have been removed either because they had already been replaced or Microsoft felt no one used them.

The NTFS features not found in ReFS are named streams, object IDs, short names, compression, EFS (Encryption File System), user data transactions, sparse, hard-links, extended attributes, and quotas.

If there's one thing likely to annoy some people about ReFS, it's the lack of a drive conversion option. The only way to convert from NTFS to ReFS is to copy the drive contents to a second drive, format the original with ReFS, and then copy the data back.

You can find more technical information on the Building Windows 8 blog.

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13 user comments

117.1.2012 10:56

It's always nice to see Microsoft implement one or two of the many features that made the Amiga great 30 years ago.


Ignorance en masse is still ignorance.

217.1.2012 11:05

Hows its ability not to lose data when you have a hard reset/crash?


Copyright infringement is nothing more than civil disobedience to a bad set of laws. Lets renegotiate them.

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Check out my crappy creations
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317.1.2012 11:53

Originally posted by ZippyDSM:
Hows its ability not to lose data when you have a hard reset/crash?
6th paragraph down would be as close as one can get to answering,basically if you overwrite instead of save your screwed is what i'm reading


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417.1.2012 11:56

Originally posted by scorpNZ:
Originally posted by ZippyDSM:
Hows its ability not to lose data when you have a hard reset/crash?
6th paragraph down would be as close as one can get to answering,basically if you overwrite instead of save your screwed is what i'm reading

So NTFS is still better?

Copyright infringement is nothing more than civil disobedience to a bad set of laws. Lets renegotiate them.

---
Check out my crappy creations
http://zippydsmlee.deviantart.com/

517.1.2012 12:10

Originally posted by ZippyDSM:
Originally posted by scorpNZ:
Originally posted by ZippyDSM:
Hows its ability not to lose data when you have a hard reset/crash?
6th paragraph down would be as close as one can get to answering,basically if you overwrite instead of save your screwed is what i'm reading

So NTFS is still better?
lol you decide

617.1.2012 12:28

#1 - I screwed up by forgetting the link. You will find more information there, about halfway down the page or so IIRC. Oh yeah, I added the link to the bottom of the article. Not sure where my head is today.

#2 - That was some really bad writing on my part. Sorry about that. Next time you see some confusing crap like that, feel free to contact me and let me know. Now I have to go back and re-read to make sure I clear it up with accurate information. Unless Andre or Jamie wrote it, in which case you should harass them instead ;)

This message has been edited since its posting. Latest edit was made on 17 Jan 2012 @ 12:29

Rich Fiscus
@Vurbal on Twitter
AfterDawn Staff Writer

717.1.2012 12:53

vurbal, you still hungover from new years?

817.1.2012 12:54

BAWAHAHAHA I miss this place I should post more!


Copyright infringement is nothing more than civil disobedience to a bad set of laws. Lets renegotiate them.

---
Check out my crappy creations
http://zippydsmlee.deviantart.com/

917.1.2012 13:05

Originally posted by ddp:
vurbal, you still hungover from new years?
More like no sleep from last night and plans not to get much tonight either.

Rich Fiscus
@Vurbal on Twitter
AfterDawn Staff Writer

1017.1.2012 13:29

little rug rats keeping you awake?

1117.1.2012 13:33

Originally posted by ddp:
little rug rats keeping you awake?
Nah, their cages are very secure and once they're worn out the screams don't carry from the basement to my office.

Rich Fiscus
@Vurbal on Twitter
AfterDawn Staff Writer

1217.1.2012 19:34

Originally posted by A5J4DX:
Originally posted by ZippyDSM:
Originally posted by scorpNZ:
Originally posted by ZippyDSM:
Hows its ability not to lose data when you have a hard reset/crash?
6th paragraph down would be as close as one can get to answering,basically if you overwrite instead of save your screwed is what i'm reading

So NTFS is still better?
lol you decide
lol

AD Guides: http://www.afterdawn.com guides/
Console Mod Tuts: http://www.realmodscene.com/

1318.1.2012 4:32

Who's the idiot that decided to remove support for Sparse files?

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