The bullseye release-notes at

https://www.debian.org/releases/bullseye/amd64/release-notes/ch-upgrading.en.html

are misleading about the needed disk space.

"apt -o APT::Get::Trivial-Only=true full-upgrade" was saying

649 upgraded, 113 newly installed, 11 to remove and 1 not upgraded.
Need to get 455 MB of archives.
After this operation, 558 MB of additional disk space will be used.

and I had around 650 MB free space, but the upgrade failed due to
lack of disk space when processing the new Linux kernel
(linux-image-5.10.0-8-amd64_5.10.46-4_amd64.deb). I tried to
complete the upgrade after another "apt clean", but this wasn't
enough (and increasing the disk space couldn't be done without
rebooting).

I suspect that some packages like this one need a lot of temporary
disk space (could this be related to initrd before compression?).
But there is nothing about that in the release notes. And perhaps
a warning should have been output by apt.

Hi Vincent,

Vincent Lefevre <vincent@vinc17.net> (2021-08-17):

455+558 >> 650 so it was very unlikely to work?

But yeah, even if the release notes mention “After the download […]”
things, it could probably point out that you should look at both
numbers, instead of just using xx.x and AAA placeholders.

There's one for the directory where debs are downloaded (which you
didn't get since 455 << 650), but I suspect it's harder to estimate
where the whole “additional disk space” is going to end up, depending on
file system layout, etc.?


Cheers,

Hi Cyril,

This is what I was wondering initially, but the release notes say:

  If you do not have enough space for the upgrade, apt will warn you
  with a message like this:
  E: You don't have enough free space in /var/cache/apt/archives/.

i.e. if the test was 455+558 < 650, the lack of space would be
detectable by apt, so that I should have got a warning. Since I
didn't get the warning, I supposed that the 455 MB were included in
the 558 MB (the last message is not clear: "additional disk space"
compared to the status before or after the download?).

The text from the release notes clearly says "for the upgrade", not
"for the download of the archives". Thus the comparison would have
been 455+558 vs 650 if 455 is not included in the 558. Perhaps it
should assume that everything goes to the same partition since
AFAIK, this is the most common case (optionally check whether
/var/cache/apt/archives and / are on different partitions); this
is just a warning after all.

In my case, there's a second disk, but mounted on /srv. So this
shouldn't count.

control: tags + patch
thanks

This one, on free space needed is hopefully addressed by
https://salsa.debian.org/ddp-team/release-notes/-/merge_requests/159

package: release-notes

# disk space
tags 992345 + patch

# usrmerge
tags 992116 + patch

# both patches are in salsa MRs