Re: [gentoo-user] Hard drive and maximum data percentage.

[Rich Freeman <rich0@gentoo.org>]

On Sun, Jan 26, 2025 at 1:15 PM Dale <rdalek1967@gmail.com> wrote:
> Still, given the large
> file systems in use, where should I draw the line and remain safe data
> wise?  Can I go to 90% if needed?  95%?  Is that to much despite the
> large amount of space remaining?  Does the percentage really matter?  Is
> it more about having enough space for the file system to handle its
> internal needs?  Is for example 1 or 2TBs of free space enough for the
> file system to work just fine?

It really depends on the filesystem.  For ext4 you can go all the way
to zero bytes free with no issues, other than application issues from
being unable to create files.  (If you're talking about the root
filesystem, then the "application" includes the OS so that isn't
ideal.)

Some filesystems don't handle running out of space well.  These are
usually filesystems that handle redundancy internally, but you really
need to look into the specifics.  Are you running something other than
ext4 here?

The space free almost always takes into account filesystem overhead.
The issue is generally whether the filesystem can actually free up
space once it runs out completely (COW might want to allocate space
just to delete things, due to the need to not overwrite metadata in
place).

--
Rich