How large is the EFI partition? What percentage of the EFI filesystem is in use? Find out with: df -hT /boot/efi

@Deltik It's ~ 500mb, usage currently is around 1%. (I've checked this in advance as well, sorry for not putting it into the question. As far as I understand the error message, this isn't about /boot/EFI, but about "something different", right?) [I'm I no way something like an "UEFI-expert", so it's quite possible that I'm completely wrong on this.]

Ah, that would be too easy, wouldn't it? The next place to look is here: /sys/firmware/efi/efivars/. These are probably the variables that UEFI system is complaining about.

@Deltik Yeah...would have been to easy. :( About /sys/firmware/efi/vars/: There is "much stuff" inside. Any idea what should I check for?

I'm taking a guess here, but this should sort the variables by size in ascending order: ls -lh /sys/firmware/efi/efivars | sort -k5 -h

@Deltik This won't work like intended: Inside /sys/firmware/efi/vars/ are many directories, all of size 0.

I miswrote earlier. Notice that /sys/firmware/efi/efivars is not /sys/firmware/efi/vars.

I see

/sys/firmware/efi/efivars appears to be an efivarfs abstracted filesystem built into the kernel, as you can see in the mount mtab.

Overlooked this, sorry; efivars/ is empty

Try this as root: mount -t efivarfs efivarfs /sys/firmware/efi/efivars

This works

However, currently, I've got no access to the machine in question

The client is on the plane

Aw

I'll get VPN access later

so...I would mount the folder, and check for the sizes?

...getting the biggest files / vars

Yeah. I think this is the best lead so far, but I don't know if something will stand out.

:)

Any idea then how to debug this further?

Or..who to speak to?

I thought about writing to debian-user@...

But actually I've got the feeling that this problem is maybe still unknown

Well, this storage is accessible to the operating system, so you should try to figure out what is writing to it.

I have no idea what it could be at the moment.

no Google search entries isn't a good sign, I think

Well, there is more documentation on efivarfs and what Linux can do with the EFI storage

@Deltik Sounds good

But I did do a Google search for "Error: The non-volatile system UEFI variable storage is nearly full." and found four manuals from Lenovo that aren't very helpful.

yeah

me too

But there isn't sth helpful inside

just "bla-bla"

in case I didn't overlooked sth

alright @Deltik, thanks for your help so far. I'll try to debug this further, and update the question in case

Ooh, check this out: apt show efivar

Tools to manage UEFI variables
 efivar provides a simple command line interface to the UEFI variable facility.

yeah

sounds good

I've got a Thinkpad myself as well

maybe it will run a diff between the two devices

and check for differences

-it +I

Not a bad idea

Well...besides this I'm a bit clueless

take a "snapshot" of the efivars after this

restore the debian boot entry

take another snapshot

Took the words right out of my keyboard

and one more after the problem starts again

and then run a diff over all these

That sounds like a brilliant plan.

<- unsure if this is "brilliant"

:)

It's what I would do if no variables jump out at me.

actually I'm thinking as well about just using legacy boot as well

all this UEFI stuff feels quite ugly

The Arch Linux wiki suggests that there may be /sys/firmware/efi/efivars/dump-* files taking up space in that UEFI storage.

got a link to this?

wiki.archlinux.org/index.php/…

ty

I feel like I'll gradually accept our UEFI overlords just like we now have to accept our overlord Lennart Poettering for SystemD.

I've changed my mind about systemd while using it since ~ a year

but UEFI feels like crap

One thing I don't like about UEFI is that the Xen hypervisor cannot load when booting in UEFI mode.

really?

omg...

:P

so Xen has to be patched to work with UEFI?

I'm using KVM (which I would totally recommend) :]

No such patch exists as far as I'm aware

I see

I'm having an issue with KVM where if I try to assign more than two virtual CPUs, the Windows virtual machine only sees two cores.

Haven't asked Super User about it yet, though.

Not sure how to word it

no idea about Windows, sorry

but maybe ask at Serverfault

instead of Superuser

Good idea

there are many wise ppl over there

not sure about superuser

I'm writing mostly on SF

I noticed. You've got 1.5k reputation there

Yeah...

But just started to write since Nov '15

@Deltik Thanks so much for your pointers, these are a good starting point! I'll debug and update the post. All the best!

You're welcome!