I have an issue that is baffling me.
I have been through all the command line processes to upgrade from 36 to 37 and eventually get told that I need (about) another 2GB.
I eventually moved (and deleted the original dirs) about 8GB from my home dir to another disc, but the upgrade process still tells me I need (about) 2GB of extra space!
I then tried a reboot and the upgrade again...similar result.
I have also run 'dnf system-upgrade clean', and gone through it all again, similar result.
Any suggestions as to what's going on here?

Cheers,
Terry

Just for clarity, I must ask whether your /home is on a separate partition from /?

Also, you might want to take a look at the du command. It might provide you with some useful information.

Good question...that occurred to me a while after I posted.
/ and /home are indeed on separate partitions, and does explain what has been happening.
/ has 12 GB available, which on the surface would seem to be enough, but must be less than needed for the upgrade.
My problem now is to identify system stuff on / that can safely be deleted. Any advice on that would be helpful, as Dr Google seems to only turn up answers that aren't relevant to this issue.
Thanks for your help thus far.

Cheers,
Terry

Thinking out loud here.

Wonder if booting to DVD the upgrade may help? On some distro they had a way to sort of easy update.

Just to check. Did you update fully before you tried to upgrade? Also clear the update cache.

Yes, I followed all the guidelines prior to upgrade.
I have been thinking that increasing the size of the / partition might be a better long term answer, and booted gparted to have a go at doing this, but didn't proceed when I was warned that changes might prevent booting.
My disc is partitioned in the following order:
ext4/boot 500MB; ext4/ 40GB; fat16/boot/efi, 190MB; ext4/home 198 GB.
What I was thinking of doing was move the start of /home to the right by 5GB (ie decreasing size by 5GB), then move /boot/efi up to the new boundary of /home, and finally increase / by the 5GB I have gained.
The prospect of causing boot issues by the above moves is not fully understood by me, and any advice would be appreciated.
Another possible long term solution would be to purchase a 500 GB system disc, but partitioning that and moving everything from my current disc is another mystery as to what dragons lurk in that process!

Cheers,
Terry

IT might be that boot partition (not the EFI) - fedora used to use that as "work space". If it's just part of the root, the problem goes away.
40G should be plenty - have a look at ncdu so you can drill down on the biggest users. I've had major issues with the PackageKit cache in the past.

If I look at the disk partitioning, /boot is mounted as /dev/sda1, and / is mounted as /dev/sda2, /home is mounted as /dev/sda5

I see that /var/cache/PackageKit has about 740MB, not really enough if you believe what the upgrade has been telling me.
I'm not sure if I use PackageKit, I always use dnf, but not sure if PackageKit is used in the background. Can that cache be cleaned out?
Are there other caches, or similar stuff in / that can be safely deleted?
No man entry for ncdu, so probably not on my system.
Good to know your biggest users but how to know that they can be deleted to make space?

Cheers,
Terry

Just to follow up on the above suggestion.
Is there a way of getting an ISO image of the upgrade for my machine? And how would one then upgrade from that?
I always assumed that an ISO would be the 'standard' distro, and then it would be a clean install, whereas I have a lot of additional stuff on my machine to build various FOSS packages, and I can imagine a lot of work to then be sure I've got it all set up as it was.

Cheers,
Terry

is /tmp mounted on tempfs? if so this might be the limitation biting you.

I don't think so.
The problem has been solved...or at least gone away until next upgrade.
I've successfully upgraded to 37, I found the space needed by temporarily moving the contents of /var/cache to another disk.
So it's greatcoats off, at least until I need any help making a long term fix.

Cheers,
Terry