Starting with the next major Windows update, Microsoft is going to reserve about 7 GB of disk space on Windows’ root drive for something it calls “reserved storage”, basically a space for updates, apps, temporary files, and system caches. Note that the 7 GB is variable, and will change depending on how you use your system.
When apps and system processes create temporary files, these files will automatically be placed into reserved storage. These temporary files won’t consume free user space when they are created and will be less likely to do so as temporary files increase in number, provided that the reserve isn’t full. Since disk space has been set aside for this purpose, your device will function more reliably. Storage sense will automatically remove unneeded temporary files, but if for some reason your reserve area fills up Windows will continue to operate as expected while temporarily consuming some disk space outside of the reserve if it is temporarily full.
In the comments under the blog post announcing this change, Microsoft’s Craig Barkhouse explains in more detail how, exactly, this feature is implemented. Instead of opting for VHXD or separate partitions – which would cause a performance hit and compatibility issues due to the files residing in a different file system namespace – the company optied for making use of NTFS. As Barkhouse explains:
Instead we designed an elegant solution that would require new support being added to NTFS. The idea is NTFS provides a mechanism for the servicing stack to specify how much space it needs reserved, say 7GB. Then NTFS reserves that 7GB for servicing usage only. What is the effect of that? Well the visible free space on C: drops by 7GB, which reduces how much space normal applications can use. Servicing can use those 7GB however. And as servicing eats into those 7GB, the visible free space on C: is not affected (unless servicing uses beyond the 7GB that was reserved). The way NTFS knows to use the reserved space as opposed to the general user space is that servicing marks its own files and directories in a special way.
You can see that this mechanism has similar free space characteristics as using a separate partition or a VHDX, yet the files seamlessly live in the same namespace which is a huge benefit.
This functionality will only be activated on fresh installations of the next major Windows update, so existing systems will not be affected.
7GB…. I could get three OS’s in that space, with room to operate too! mind you I do end up reserving a whole device for the OS, you never can trust it not to mess with things otherwise….
codifies,
No worries, I’m sure microsoft will pay owners handsomely to rent this space that users will no longer have access to in the future.
It does beat microsoft update deleting your files.
https://www.zdnet.com/article/windows-10-october-update-delete-your-files-this-tool-might-recover-them/
/sarcasm
I think they have a different definition of the word elegant than i do….
It would be nicer if they made things simpler instead of even more complex, and it would be nicer if they focused on not filling up the disc with crap, that you later have to run tools like their own disc cleanup thingy to reclaim. With simpler i don’t mean sweeping them under the bed so they are out of sight,
Wonderful! A reserved area of my disk that might spill over unpredictably, and that I can’t designate for some other purpose. With hidden and special files galore. I suspect malware writers are going to have some wet dreams over this one. All to hide a problem that should be solved, namely that Microsoft’s update mechanism is a broken, bloated, and unpredictable piece of unmaintained garbage!
So Windows has caught up with Linux then? See :-
¡ tune2fs -l /dev/mapper/boot-root | grep “Reserved block count”
Reserved block count: 781209
Reserving space to avoid dealing with a completely full file system isn’t the worst sin in the world and has been done for decades under Unix/Linux.
MikeMe,
It seems quite a bit different though, the 5% default reservation on linux is for the root account to be used for anything at all. It’s not earmarked for the distro and it can even be disabled. Microsoft’s post seems to indicate this ~7GB is not accessible or changeable by users, furthermore they specifically say 7GB isn’t a hard limit, the reservation will increase as you install more windows features.
The example discussed in the comments…
It’s not that having a reservation is a bad thing, I just don’t like it being microsoft specific. But as with the updates themselves, the issue could end up being a lack of owner control for professionals and power users on their own machines. I guess we’ll see if that’s the case here, but as microsoft takes control away it tends to increase resentment.
Dear Microsoft Windows,
You don’t own my hardware. Stop acting like you have free reign to do whatever you want. Now f* off and go back to being an OS instead of a nanny/PC police.
……….Thanks