I have a half dozen Hyper-V virtual machines and will add a few more. I have been storing the vm files on my Storage Space (formatted ReFS). Load times are OK but I have decided to dedicate a Crucial MX300 525gb SSD for vm file storage instead. I have no qualms using them on ReFS but of course I will store other data on the SSD from time to time as well.
Question: If you have experience in using ReFS for data drives please share with me the pros and cons in your opinion.
Note: I already know that saving image backups or any disk and partition backups from third party backup solution providers is a very bad idea at present. I don't plan to do that. I also know about the bug in the Anniversary Update and the subsequent insider builds that requires turning ReFS formatting on and off and when to do it.
I look forward to sharing experiences.
I always say to people: unless you're using ZFS, Btrfs or ReFS on a file server, do not ever think your data is OK. I run a 2012 R2 Datacenter server (also testing Win Server 2016 Datacenter which I am looking forward to migrating my server to), where I use ReFS for virtualization primarily, but any workload of Hyper-V deployment outside of Storage Spaces is significantly optimized due to its aggregated cluster resiliency. That said, ReFS does not support deduplication so on grounds of you mentioning your average backup/restore being a definite no-no is spot on. That said, there are ways to backup/restore ReFS but you hardly need to begin going into that.
Keep in mind that ReFS is primarily for archival storage and with using ReFS for archival storage, you do not ever have to worry about the status of your data as being optimal and in-tact. Many people who run servers will gloat over what their server hardware and server monitoring software says, but none of that will tell you diddly-squat about the data itself. Data protection requires a proactive approach, and you start by choosing a file system that is designed for data resiliency.
Now on my NAS I run ZFS which does support deduplication, but it's a file system Windows will probably never "understand." My server is mainly for CA-certificate signing/issuing, custom OS deployment, updates, remote virtualization and hosting, but my NAS is what is used for actual encrypted and secure backups. That said, ZFS is utterly fantastic and ReFS is its much smaller brother from another mother (Windows). No need to get into ZFS now, though.
I have tested the ReFS' resiliency on my server by creating a large pool of Storage Spaces across 3 physical spare drives, and then hot-unplugging a drive inside the server itself and watching for when the server signaled the loss of the drive. I then ran checks on the remaining 2 drives and all data was in-tact and there was zero corruption or issue at all. ReFS does its job and does its job very well.
To sum it up fairly quickly, ReFS is really designed primarily for virtualization and archival data storage. It is leaps and bounds more robust than NTFS and the best Windows has to offer right now, and it will replace NTFS in a few years. There are no issues running it on a drive alone so long as you're aware of the drawbacks before taking the plunge.
For new people thinking about ReFS, The best way to get involved with ReFS is slowly and utilizing Storage Spaces before moving onto using it on a physical drive; however, if a drive is going to be purely for file storage, you won't have to worry about anything on your end. Just leave it alone with your data and it'll all be gravy.
Thank you for sharing your thoughts. I hope others are following this thread. I am exploring ReFS in a desktop environment to see how far I can get with it and so far it is doing its job quietly and reliably, but opportunities to apply it are sometimes limited. So far I am using it as you suggest, for archiving and virtualization. I look forward to when Microsoft moves it into production for general purposes and third party backup providers get on board. I am pounding at them with feedback to say that it is time.
Also keep in mind that ReFS is not entirely bug-free when it comes to using it on a physical drive and not a virtual environment. Many, many people have had problems arise formating a physical drive in ReFS (i.e. Bitlocker no longer working properly, high system process percentage by a service named ""Microsoft.NET Error Reporting SHIM," etc.) These have been reported as system-wide issues, too, and affect all drives. Luckily all you have to do is remove the registry key for ReFS activation and all goes back to normal. Just keep an eye on things.