[systemd-devel] [Help] Can't log in to homed user account: "No space left on device"

[Andrii Zymohliad]

> As far as I can tell if discards are disabled, systemd tries to allocate
> full size of backing file. It is possible that there is simply not
> enough space to ensure full 400G (i.e. available space it consumed by
> something else). Are there are snapshots

Sorry, I think I lack some background to fully understand what you wrote. Do you mean if I had "discard" mount option enabled on both home and root filesystems, it would not need to allocate the full size of home partition file?

First thing that confuses me is, why I have less than 400G allocated on my root partition before authentication if home file is 400G? I thought that in case of LUKS, /home/azymohliad.home should be an opaque file that always takes 400G on the root filesystem. But `btrfs fi du /home` shows that it's only 256G (which is the actual usage of internal partition on it). `btrfs fi usage /` shows that I have 176G free space, which as I understand should be enough to allocate the remaining 400G - 256G = <150G for home, although I suppose simple arithmetic doesn't work here, I'm not really familiar with btrfs.

Not sure what are snapshots, but I haven't made any explicitly.


> Try enabling debug log level, this will give more details about what
> happens.

I added these kernel arguments:

    systemd.log_level=debug systemd.log_target=kmsg log_buf_len=1M printk.devkmsg=on enforcing=0

Here is the log after authentication attempt: https://gitlab.com/-/snippets/2007113
And just in case here is the full log since boot: https://gitlab.com/-/snippets/2007112