Jaga

A couple of pics (one from MSM), + one of my brand new Mid Plane mounting solution (I'm now just using the 2 x SFF-8088 to 8088 Cables to connect to the M1015 and I'll leave the others if I ever need to use the External SFF Board for more storage goodness).  Love how you can just plug these expanders in and they just work without any mucking around.  

 

Yeah. But there are always variations on how the files are placed, and such.  As well as metadata that you don't see. 
Also .... if you're using reparse points, and a LOT of them, .... that may be why too. 
Depends on the usage, but yeah, it can help with I/O load, as it may spread it out between the disks better. 
And the Read Striping feature helps to optimize the reads, too. 
Duplicated data is written out to all destination disks.  So if you're using the SSD Optimizer balancer, and duplication, then you need two SSDs, or the second copy is written out to an "archive" drive, and may/will slow down the write speeds.    having 2x SSDs, (or ... a number of SSDs equal to the highest level of duplication that you're using) means that both/all copies are written out to the SSD drives, and not the archive drives. 
Real time duplication can be disabled, but that means that new files won't be protected by duplication for up to 24 hours! 

You'll want to use File Placement Rules on folders to ensure they stay on specific drives.  Balancing settings, File Placement tab, Folders tab.
https://stablebit.com/Support/DrivePool/2.X/Manual?Section=File Placement
If your files are currently spread out over multiple disks (per folder) you will want to setup the desired rules, then initiate a re-balance to have it move them into place.

Suggestion:  pick up a copy of PingPlotter, enter in googleapis.com, set it for 5 or 10 second resolution, then run it.  You get 14 days on the Standard/Pro edition to collect unlimited samples, and can switch to the free edition after that.  See what kind of reliability you get over 24/48 hours, and what kind of pings you get on each hop.  It might indicate any problems along the route, or if your connection drops out entirely.  Attached a sample plot on my VPN connection to this post so you can see the kind of info you get from it.
You can always just run a ping test from a command prompt, but lose detail on each hop that way.
I used this method when proving to my ISP that there were connection issues.  It helped me to successfully get the FCC involved and force the ISP to fix their hardware.
Edit:  I left mine running a little while after making this post, and the IP resolution changed on-the-fly.  That's DNS and/or Google doing it, not me.  Really nice info you can get on packets and hops this way.
 

This may be relevant:
But basically, the "size" and "size on disk" are often not the same.
If you have a lot of small files on the disk, then this can happen. Especially if you formatted the disks with different "allocation unit" sizes.
 

Okay, good news everyone.
Alex was able to reproduce this issue, and we may have a fix.  
http://dl.covecube.com/ScannerWindows/beta/download/StableBit.Scanner_2.5.4.3198_BETA.exe
 

Just a quick update...the JSON files are located in the directory that Jaga mentioned. I manually entered all my custom drive names and settings one more time and did a reboot after the latest Windows update. The settings seemed to stick this time.

Jaga is correct here. 
And if it's not storing the settings at all, then there is another issue here, and ... resetting the settings manually may fix the issue:
http://wiki.covecube.com/StableBit_Scanner_Q4200749
Eg, delete the entire "C:\ProgramData\StableBit Scanner" folder, and restart the service.

Edit:  moved suggestion to other topic..
 

The import/export feature would be nice. I guess right clicking on the folder and 7zip'ing it, is the definitive solution, for now, until an automated process evolves.
According to Christopher's answer that it seems to be an isolated incident, I'm wondering what is it about our particular systems that is causing this purge? 
I have it running on both W7 and W10 and it purges on both. Both OSs are clean installs. Both run the same EVO500...alongside a WD spinner. Both are Dell. It seems to me that the purge is triggered by some integral part of the software once it's updated. Like an auto purge feature.
I'll be honest, I think most people are too lazy to sign up and post the issue, which makes it appear to be isolated incident, but I believe this is happening more often than we think. 
I'm on a lot of forums, and it's always the same people that help developers address bugs, by reporting them. Unless it's a functional problem, it goes unreported.
All of you...know how lazy people are. With that said, I like the idea of an integral backup and restore of the settings. 

Might be a nice option to have an import/export function for the settings in the various products.  Primocache and Primo Ram Disk have it, and I use them when re-creating configs all the time.  It has saved my bacon more than once.  Just bundle the JSON folder into a .zip and allow the user to specify export destination.  On import, unbundle and write (with optional overwrite verification).  Just a suggestion.   

As per your issue, I've obtained a similar WD M.2 drive and did some testing with it. Starting with build 3193 StableBit Scanner should be able to get SMART data from your M.2 WD SATA drive. I've also added SMART interpretation rules to BitFlock for these drives as well.
You can get the latest development BETAs here: http://dl.covecube.com/ScannerWindows/beta/download/
As for Windows Server 2012 R2 and NVMe, currently, NVMe support in the StableBit Scanner requires Windows 10 or Windows Server 2016.

Many people losing settings on updates recently.
 

So then, it's the StableBit DrivePool metadata that is duplicated then.  This ... is standard, and it's hard coded to x3 duplication, actually.
We don't store a lot of information in this folder. But reparse point info IS stored here (junctions, symblinks, etc).  So if you're using a lot of them on the pool, then that would by whey you're seeing this behavior.  And in this case, you don't want to mess with this folder. 

I used Z once, only to find that the printer with some media card slot wanted it itself or would not print at all. Same for some Blackberry devices caliming Z. So yeah, hi up but not Y and Z.
I use P, Q and R.

That was my conclusion back in 2011 and I don;t think it has changed (but I have not really looked except for Macrium which currently I think is not for me and not as good as WHS even).
To my horror, I just found out that M$ is abandoning the Essentials role (and thus I assume Essentials entirely) in Server 2019, which I would go for! Apparantly the intended replacement is Microsoft 365 for business (https://www.microsoft.com/en-us/microsoft-365/business). The site reminds me of the marketing spoof where M$ re-designs the ipod packaging: No clue what it says. And boy, is it expensive!
So it may be I need to go WSE 2016 and that wil be EOL for me. I hate it that I'll have to invest quite a bit of time and only be able to rely on this until early 2022.

Sorry, I missed that.  It's been super hot here, and I don't deal well with the heat.  I'll try to make sure I'm better.
Also, I did pass this information on to Alex.  The NVMe 1.1 may or may not be the issue.  Eg, we may want/need to implement it as well, or it may be a red herring. 
As for the SATA based one, if you use the DirectIO Test tool, see if any of those actually get the SMART Attributes for the drive:
 

Which isn't a bad idea.  But personally, I don't like using Z, since ... that seems to be the go to for mapped network drives. 
But as long as it's further along in the alphabet, it should avoid this issue. 

I assign all my pool drive letters in reverse, starting at Z.  Seems to help avoid issues like this.

This is a Windows issue, actually.  It auto assigns the drive letter, and can bump the letter like this.  
 
The best recommendation here, unfortunately, is to assign a letter that is much further along in the alphabet (such as "P:\" for Pool, or "S:\" for Storage), as this should prevent it from being reassigned a letter. 

Sounds like you might need to rebuild the Windows thumbnail cache.  It's a good thing to do periodically even if you aren't having problems.  You didn't say what OS you are on, so I'm assuming it's W10.  Here are some instructions for doing both the thumbnail cache, and icon cache.
https://www.thewindowsclub.com/rebuild-icon-clear-thumbnail-cache-windows-10
 
Separately, I use a shell extension called Icaros, which gives Explorer better control and caching options for thumbnails (including indexing of specified folders).  If you've cleared your cache and Windows still isn't displaying them properly, you might give it a try.

This should be fixed in the release version. 

Windows Server Essentials DOES NOT require CALs.  It includes access for a number of systems/users built in.  Though that number depends on the specific OS version.   Unless you're going past that limit (25 or 50, IIRC) then you DO NOT need CALs.  Period. 
I think you're misunderstanding.  The 2 concurrent logins isn't for users accessing resources on the system, but for login sessions. Eg console login (mouse, keyboard, video) and Remote Desktop.   You have have all 25 users logged into their own systems, and accessing resources without any issues. 
That's some Grade A screw up. It's 1 system, 2 Processor sockets. 
https://docs.microsoft.com/en-us/windows-server-essentials/get-started/system-requirements
So please ignore whatever this says. It's wrong.  When in doubt, go to Microsoft
Welcome to Microsoft Server.
Joking aside, see above.    It's two users logging in, not a limit on accessing devices.  
Because I have 8 different machines all connecting to the server, over the domain.
Next time, put an @ symbol before my name. It tags me and lets me know. 
Eg @GDogTech or @Christopher (Drashna) 
 
That's the problem with buying retail. It's much more expensive.  OEM is better, but ... harder to get, and has other (licensing) issues.

Umfriend: I do actually use WHS for client backups, I said it’s just not the one I RELY on, that’s really all. Reason is because WHS has failed to restore about half of the PC’s I have asked it to do. Macrium Reflect has NEVER let me down. In addition, this way I have 2 sets of backups, which can’t hurt except for the drive space required to have it. 
BTW: Regarding the backup thing, consider this: Macrium Reflect is fully network aware, and full or incremental image backups can be scheduled to happen automatically, in the background, at any degree of bandwidth, at any chosen time, written to any network share or connected PC, with post-backup verifications and terminations. All this is in the FREE version. The Paid version allows differential and file backups as well. So, if backup is the only reason YOU are using WHS2011, then I ask you: Why are YOU using it?
Also, don’t forget that WHS2011 was WAY CHEAP compared to these newer Server OS’s. If you recall, it was never sold as a Retail package. You could buy it in the retail channel (I bought my copy through Newegg for like ~$50), but it was only ever intended to be sold to entities that manufactured their PC’s as OEM's. This could describe me and every PC I have ever owned except for the Laptops. At the time, $50 was about 1/3 the cost of any other OS MS was selling.
As far as what I use it for, besides the secondary backups, I just use it mostly as a Media Server to stream my collections of Music, Movies and Misc Videos. It is by far the most stable OS I have ever had. Each of my Family members has their own Shares, but I am not sure what they are using those for beyond storage of mostly their music.
Are you saying that I can do these things just as effortlessly with any MS Desktop OS??? I never really considered that, but I might now if we can’t resolve this concurrent user thing brought up by Jaga!

I've updated the article to reflect this, so it shouldn't be an issue in the future.