Today when I logged into one of my ervers I was unable to create a file as I was told that No space was left on device. I checked my discs for free space and found that free space exists on all of my partitions, that’s why I got stuck. I was able to modify my existing files but had no possiblity to create new ones. I even could not start Midnight Commander: it could not create a temporary file.
This usually occurs when your space is used at 100%, but it is quite a rare situation. Most probably you have free space on your partition, but have exceeded the number of files that is allowed to be stored within it.
I cannot tell you what is the number of files permitted, but if you have lots of temporary files, you should really take care of its number. I’d suggest you to delete temporary files when they become unusable as it’s quite hard to detect this issue if you don’t know where they are stored (let’s suppose you have many user accounts and it’s not so easy to detect which of them has a big number of unnecessary files.