Jump to content
RESET Forums (homeservershow.com)

ReFS (vs NTFS) and VHDs


timekills
 Share

Recommended Posts

I've replaced my 2008R2 with Server 2012. I have a 600GB Velociraptor that is my primary VHD storage drive. I've already taken the plunge and formatted my RAID6 array using ReFS because I'm more interested in the "self healing" available with ReFS than the de-duplication space saving that is available if I stayed with NTFS. But for the VHD storage, is there any advantage/disadvantage in formatting the drive as ReFS? 

 

I've seen very few benchmarks for ReFS vs NTFS drives, and they all seem to be older (mostly pre-final 2012 release.) They all show a (small) increase in speed for ReFS, which is important for VHD storage. 

 

Anyone have any practical experience with ReFS and VHDs for Hyper-V, or any thoughts?

Link to comment
Share on other sites

I wasn't that impressed with ReFS. Check the performance summary in Table 1 in http://homeservershow.com/storage-spaces-performance-in-windows-server-2012-essentials-on-a-hp-n40l-proliant-microserver.html

 

I wouldn't use it for my VM drive -- I've gone NTFS and dumped my ReFS volumes for now.

 

On my Hyper-V server (S2012) I'm using a Storage Space but just a NTFS thin mirror.  I used a Simple NTFS thin for awhile but it's a real PITA if you want to take a HDD out of the Storage Space -- you can do it with Mirrors but not Simples though the performance of a Simple is nice there's more risk.  

Edited by Joe_Miner
Link to comment
Share on other sites

I wasn't that impressed with ReFS. Check the performance summary in Table 1 in http://homeservershow.com/storage-spaces-performance-in-windows-server-2012-essentials-on-a-hp-n40l-proliant-microserver.html

 

I wouldn't use it for my VM drive -- I've gone NTFS and dumped my ReFS volumes for now.

 

On my Hyper-V server (S2012) I'm using a Storage Space but just a NTFS thin mirror.  I used a Simple NTFS thin for awhile but it's a real PITA if you want to take a HDD out of the Storage Space -- you can do it with Mirrors but not Simples though the performance of a Simple is nice there's more risk.  

 

That article - and most other benchmarks - are really benchmarking Storage Spaces, not ReFS pure. I'm not using Storage Spaces. However I'm seriously contemplating formatting the RAID6 array in ReFS (NOT using Storage Spaces) just because of the occasional issues with using it in pass through mode. The VM is unable to do physical drive checks on the RAID array so when there are errors I have to pause the VM (in this case WHS2011), go into the host OS (formerly 2008 R2), bring the array back online, do a CHKDSK through the host OS, fix the errors, bring the drive (array) back offline, and restart the VM.

 

My thoughts are using ReFS that these little errors won't arise, and therefore won't require this relatively frequent procedure. As long as the speed is approximately the same as NTFS, the enhanced drive repair is worth it. Any NON-Storage Spaces benchmarks I've seen - i.e. just the same drive(s) formatted with ReFS vs NTFS - show relatively the same performance.  

 

 

I did a bit of testing but did not see too much of a difference in performance.

 

The question I guess then is there any drawback to using ReFS for the the VHDs. Some gotcha I'm not thinking of. I know there are some file management programs that won't work with ReFS, but the actual VHDs won't be ReFS, just the host drive for them. I'd think the self-healing would be a big benefit for VHD hosting.

Link to comment
Share on other sites

That article - and most other benchmarks - are really benchmarking Storage Spaces, not ReFS pure. I'm not using Storage Spaces. However I'm seriously contemplating formatting the RAID6 array in ReFS (NOT using Storage Spaces) just because of the occasional issues with using it in pass through mode. The VM is unable to do physical drive checks on the RAID array so when there are errors I have to pause the VM (in this case WHS2011), go into the host OS (formerly 2008 R2), bring the array back online, do a CHKDSK through the host OS, fix the errors, bring the drive (array) back offline, and restart the VM.

 

My thoughts are using ReFS that these little errors won't arise, and therefore won't require this relatively frequent procedure. As long as the speed is approximately the same as NTFS, the enhanced drive repair is worth it. Any NON-Storage Spaces benchmarks I've seen - i.e. just the same drive(s) formatted with ReFS vs NTFS - show relatively the same performance.  

 

-snip-

 

True in an "absolute" sense but if your alternatives are NTFS and ReFS I believed that relative performance of the two when all else is equal (which is what I tried to do) to be good information.  In a sense all things are relative :)

 

You've certainly raised my curiosity and I always enjoy the detail of your postings -- please post what you learn along the way.

Link to comment
Share on other sites

True in an "absolute" sense but if your alternatives are NTFS and ReFS I believed that relative performance of the two when all else is equal (which is what I tried to do) to be good information.  In a sense all things are relative :)

 

Very good point; I shouldn't have dismissed it in hand simply because it is using Storage Spaces. I am curious why you think ReFS is not that impressive given your benchmarks. The read speeds are 2-3X faster than NTFS on equivalent setups. Granted, the *write* speeds were horrendous, which I wonder if is due to the error-checking causing a problem with caching. That write speed worries me for a VHD storage drive, but the read speed indicates it would be great for my RAID array.

Link to comment
Share on other sites

If you look at the mirrors or the Parity resiliency the ReFS write's do get hammered (NTFS writes get hammered in Parity also) but with the simple resiliency thin the NTFS and ReFS (Drives E & F) the NTFS and ReFS look pretty comparable -- it may be worth a try!  I'm guessing the VR would resemble more a Simple resiliency than a Mirror or Parity.  Are you going to do this on a RAID 6?  Are you using a 2720 for your RAID?

 

I was really disappointed in the performance of the ReFS compared to the NTFS in the 2-Way Mirror resiliency mostly because the Writes were so dismal compared to the Read performance -- so that was weighing heavily on my opinion that ReFS wasn't ready for "Prime Time" -- I was expecting it to track NTFS albiet slower maybe due to the error-checking calcs.

Link to comment
Share on other sites

Yes; I'm definitely going to format the RAID 6 (using the 2720 card) array with ReFS and give it a go. I'm still not decided about whether to format the Velociraptor (VHD storage drive) as ReFS.

 

I've run into a snag slowing my trials down. Presumably unrelated, but after enabling Hyper-V role and then upon rebooting Server 2012 it hangs at the blue Windows icon screen. As in, hangs for 12+ hours, even after multiple forced reboots. I've seen some questions on Google about slow boots after enabling Hyper-V but this is hung, I'm pretty sure. I'll continue this issue in another thread, and hopefully get back to the ReFS vs NTFS discussion soon,

Link to comment
Share on other sites

it is. Odd. I've reloaded the OS and only done the Windows updates - which is an issue itself, as there are quite a few failed updates, and per Google and MS TechNet this is not unusual although MS has not responded yet. Even just rebooting after updates is a painfully long process. I've heard some comments about USB3 issues so might try disabling it just to see if it makes a difference.

 

If there were a Server 2012 section, I'd start a new thread on this issue since I'm curious who else might be having this problem here. Have you figured out any solutions?

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...