[Eduardv]

Building the next generation file system for Windows: ReFS



Quote:

We wanted to continue our dialog about data storage by talking about the next generation file system being introduced in Windows 8. Today, NTFS is the most widely used, advanced, and feature rich file system in broad use. But when you're reimagining Windows, as we are for Windows 8, we don't rest on past successes, and so with Windows 8 we are also introducing a newly engineered file system. ReFS, (which stands for Resilient File System), is built on the foundations of NTFS, so it maintains crucial compatibility while at the same time it has been architected and engineered for a new generation of storage technologies and scenarios. In Windows 8, ReFS will be introduced only as part of Windows Server 8, which is the same approach we have used for each and every file system introduction. Of course at the application level, ReFS stored data will be accessible from clients just as NTFS data would be. As you read this, let's not forget that NTFS is by far the industry's leading technology for file systems on PCs.

This detailed architectural post was authored by Surendra Verma, a development manager on our Storage and File System team, though, as with every feature, a lot of folks contributed. We have also used the FAQ approach again in this post.
--Steven

PS: Don't forget to track us on @buildwindows8 where we were providing some updates from CES.

The key goals of ReFS are:

•Maintain a high degree of compatibility with a subset of NTFS features that are widely adopted while deprecating others that provide limited value at the cost of system complexity and footprint.
•Verify and auto-correct data. Data can get corrupted due to a number of reasons and therefore must be verified and, when possible, corrected automatically. Metadata must not be written in place to avoid the possibility of "torn writes," which we will talk about in more detail below.
•Optimize for extreme scale. Use scalable structures for everything. Don't assume that disk-checking algorithms, in particular, can scale to the size of the entire file system.
•Never take the file system offline. Assume that in the event of corruptions, it is advantageous to isolate the fault while allowing access to the rest of the volume. This is done while salvaging the maximum amount of data possible, all done live.
•Provide a full end-to-end resiliency architecture when used in conjunction with the Storage Spaces feature, which was co-designed and built in conjunction with ReFS.

The key features of ReFS are as follows (note that some of these features are provided in conjunction with Storage Spaces).:

•Metadata integrity with checksums
•Integrity streams providing optional user data integrity
•Allocate on write transactional model for robust disk updates (also known as copy on write)
•Large volume, file and directory sizes
•Storage pooling and virtualization makes file system creation and management easy
•Data striping for performance (bandwidth can be managed) and redundancy for fault tolerance
•Disk scrubbing for protection against latent disk errors
•Resiliency to corruptions with "salvage" for maximum volume availability in all cases
•Shared storage pools across machines for additional failure tolerance and load balancing



Source: Windows 8 Blog

http://blogs.msdn.com/b/b8/archive/2012/01/16/building-the-next-generation-file-system-for-windows-refs.aspx

 

[HardheadedMurphy]

Nice, raid without the raid I guess....
Or am I reading this wrong?

 

[Eduardv]

Quote:

Originally Posted by HardheadedMurphy

Nice, raid without the raid I guess....
Or am I reading this wrong?

If you are talking about data Striping,the yes,a file can be allocated in 2 physical drives, hopefully with RAID?This provides more data access throughput, which avoids causing the processor to idle wait for data access.However i can be wrong, I am interested in this hoever i dont know much about it

What i see more interesting is:

•Disk scrubbing for protection against latent disk errors
•Resiliency to corruptions with "salvage" for maximum volume availability in all cases

 

[Vowels]

Introduced in Windows Server 8? Will there be a way to use it with consumer Windows 8?

 

[Eduardv]

Quote:

Originally Posted by Vowels

Introduced in Windows Server 8? Will there be a way to use it with consumer Windows 8?

Yes,Windows 8 will be ReFs capable.

 

[sticks435]

Quote:

Originally Posted by Eduardv

Yes,Windows 8 will be ReFs capable.

Isn't the consumer version of 8 using NTFS still with some hooks to be able to access and read ReFS? It won't be the full blown file system until probably windows 9 if I read that right.

 

[Eduardv]

Quote:

Originally Posted by sticks435

Isn't the consumer version of 8 using NTFS still with some hooks to be able to access and read ReFS? It won't be the full blown file system until probably windows 9 if I read that right.

I am afraid so,they wont push the entire filesystem at once,it will be done with incremental upgrades.However we will se good portion in Windows 8,to the part in wich we can creat ReFs volumes.

For compatibility reasosn Windows 7 will be able to read ReFS volumes but it cant access it.

 

[Dock #89]

Reason enough to buy Windows 8 just to play with this. I wonder if it would be possible to run a separate drive with the new file system to take advantage of it while still running Windows 8 on NTFS?

 

[Zero4549]

Every time a new windows version is announced, they claim to overhaul the file structure... I'm still waiting, windowx XP!

 

[BizzareRide]

Its like it has built-in TRIM-like support. I'm so glad I get Windows for free through my engineering department at school! Personally, I don't see anything wrong with the current file system. I thought the biggest under-the-hood news for Windows 8 was the registry was getting a revamp.

 

[Eduardv]

Quote:

Originally Posted by Dock #89

Reason enough to buy Windows 8 just to play with this. I wonder if it would be possible to run a separate drive with the new file system to take advantage of it while still running Windows 8 on NTFS?

Well i think so,yes,as far as ive read.

Quoting from the original article
Quote:

Code reuse and compatibility

When we look at the file system API, this is the area where compatibility is the most critical and technically, the most challenging. Rewriting the code that implements file system semantics would not lead to the right level of compatibility and the issues introduced would be highly dependent on application code, call timing, and hardware. Therefore in building ReFS, we reused the code responsible for implementing the Windows file system semantics. This code implements the file system interface (read, write, open, close, change notification, etc.), maintains in-memory file and volume state, enforces security, and maintains memory caching and synchronization for file data. This reuse ensures a high degree of compatibility with the features of NTFS that we're carrying forward.

 

[Riou]

Quote:

Q) Can I boot from ReFS in Windows Server 8?

No, this is not implemented or supported.

Hmmmmm...so only on the storage drive. Also, ReFS seems to only be implemented on the Server edition.

 

[armourcore9brker]

I couldn't help but laugh at this:
Quote:

As you read this, let's not forget that NTFS is by far the industry's leading technology for file systems on PCs.

Yup, a filesystem introduced in 1993 is light-years ahead of anything on the Linux side.

 

[Riou]

Quote:

Originally Posted by armourcore9brker

I couldn't help but laugh at this:
Yup, a filesystem introduced in 1993 is light-years ahead of anything on the Linux side.

It is Microsoft after all.

They have to hype their own products as the best.

Linux already has stuff like LVM for over a decade.

 

[DuckieHo]

Quote:

Originally Posted by BizzareRide

I don't see anything wrong with the current file system.

I can think of at least a half dozen....

A lot of people predicted that the concepts of Windows Home Server Drive Extender would eventually be in the core OS.

 

[flyboy12321]

Mmm, a 18446744073709551615 byte file, awesome.

 

[Z Overlord]

Quote:

Originally Posted by Riou

Quote:

Q) Can I boot from ReFS in Windows Server 8?
No, this is not implemented or supported.

Hmmmmm...so only on the storage drive. Also, ReFS seems to only be implemented on the Server edition.

Only for now it can't be booted from.

 

[flamingoyster]

The fact that this is built on top of NTFS: good or bad?

 

[Zero4549]

Quote:

Originally Posted by flamingoyster

The fact that this is built on top of NTFS: good or bad?

bad

 

[Crazy9000]

Good to see them making the moves to replace the ancient NTFS. Remember the "NT" comes from Windows NT, this is some OLD stuff.