What would happen if you filled an HD or SSD to the last byte? Would it stop the pc from functioning?



What would happen if you filled an HD or SSD to the last byte? Would it stop the pc from functioning?

In: Technology

I don’t think most modern os let you. but a 100% full hdd or ssd would be incredibly slow if it functioned at all. they need space to shuffle stuff around.

Yes. Modern operating systems like Windows use a portion of your hard drive to store some temporary files it needs to function. It may also use your disk as extra memory if your onboard memory gets over utilized.

For this reason, there has to be some space available for these temporary files. Windows for sure (other OSs too, probably) has some alerting that is built in to start warning you when your space is getting low. You can change when this occurs in the performance/alerts section, but I believe the default is 10% remaining.

Continuing to fill up your disk space will result in gradual increases in performances issues until your computer is pretty much unusable and it becomes difficult to even delete files to free up space as even the act of deleting files takes up some temporary space.

Lots of factors at play here. Usually the operating system reserves some disk space for it’s own critical operations, some applications may crash due to poor handling of unexpected errors from the file system when trying to create files. Ultimately the operating system should be able to survive even with a read only disk…

Theoretically it would cause massive performance problems since most operating systems rely on having spare drive space for swap space and holding temp data and logs and stuff.

However, in reality modern operating systems all have mechanisms in place to reserve the space they need and not let you make the drive that full in the first place. Depending on which OS we’re talking about it might claim you’ve filled up 100% of the space but what it really means is “you’ve filled up 100% of the space **that’s available to you.**”

On a Windows 10 machine even getting down to your last 2 – 3GB will cause problems. Typically the ability to print is the first to stop working, as every print job spools to a temp file first, and the print spooler service won’t work if it doesn’t have hard drive space.

Yes. Learnt this from log files on production. Fun fact – just before the last byte you start seeing some extremely strange behaviour

Imagine your home. If you overfill it with furniture, then to walk from one room to next, you would have to move a few pieces of furniture around.

So while your home’s overall space doesn’t change, the amount of furniture in it if overdone can turn a 5 second walk into 3 minutes of exercise – a situation best avoided.

Same with storage space on PCs – leave 10% free on large drives (32GB+), 20% on smaller ones (16GB and less). 16 to 32 – Grey area, try for 15% (for typical home usage)

I’ll be a little pedantic but it’s important to remember that the hard drive already is loaded from beginning to end with information, even if they are 0’s. It’s just not earmarked as being something to keep. After a while your drive is probably loaded with random strings of 0’s and 1’s but there are large sections that are not marked as being “data”. All that ever matters is whether the OS thinks something is worth keeping or not, and how it follows those rules.

At the same time, even if a section is marked as being “saved” you could easily overwrite lots of entries with random information and never notice the difference in reality. As long as you didn’t hit any critical program code, registry entries, etc, or actual data information that you happen to consume such as photos/videos which you would quickly notice. But those make up a small part and a blip or two here, blank frame in a video there would often go unnoticed but it depends on how that data is encoded – sometimes it doesn’t matter if information is missing or corrupt, other times it basically renders the entire file unrecoverable if there’s just 1 tiny error.

When a hard drive actually “fills up” what is happening is that it can’t physically fit a piece of data anywhere on the drive because everywhere else is marked as, “do not overwrite me”. It could probably do it anyway but that’s breaking the golden rules. And it’s more complicated because the data is fragmented into pieces that are stored all over the place, so as the non-earmarked spaces continues to diminish it becomes harder and harder to fragment a file in order to fit it all in those non-marked spots, to the point your computer is barely hanging on just because it takes so long to find those open spaces. Calculating the way in which to fit something into the few open spaces may require some of that space itself.

It can be such that even though your file would theoretically break down and fit into those unmarked spaces, that it can’t work anymore because of the extra overhead required to label all the pieces, and count everything. So you’re talking about making sure you have enough room for your file, plus enough room to calculate if you have enough room for your file, plus if you have enough room for that, repeated until something stops checking if it can.

At some point a running program will never get an answer for a HDD write, and even if it’s coded well for errors it has to fall back on the platform above it, which also will be out of space to continue. Even if every thread up the chain was carefully coded to handle out-disk-space problems you eventually run out of parent threads and the basic premise of the computer itself (assuming you have some hard disk space) doesn’t work anymore and it would shit itself.

I process a lot of data at work. It’s a constant battle. I fill up my hard drive every week and have to move stuff off.