shut down cannot unmount /nix/store

[maggesi]

On several machines I get an error on shoutdown:

Could not unmount /nix/store: Device or resource busy
Not all file system unmounted, 1 left.
Cannot finalize remaining file systems and devices, giving up.
[ 859.088793] System halted.

And the computer do not turn off automatically.

[vcunat]

I already encountered too short systemd timeouts (my filesystems are quite fragmented).

[viric]

I think this was mentioned either in another issue, or in nix-dev. In any case, I experience this in every machine too.
'halt', as it doesn't power off, it's an easy way to see the related messages.

[viric]

Btw, the error unmounting appears in a "[ OK ]" systemd line.

[modulistic]

I feel this issue might come from the upstream kernels as it is happening
to me lately in some boxes running opensuse and ubuntu. I'm afraid I have
paid not much attention as these boxes are not in production.
On Mar 28, 2013 2:35 PM, "viric" notifications@github.com wrote:

I think this was mentioned either in another issue, or in nix-dev. In any
case, I experience this in every machine too.
'halt', as it doesn't power off, it's an easy way to see the related
messages.

—
Reply to this email directly or view it on GitHubhttps://github.com//issues/126#issuecomment-15588481
.

[edolstra]

We should probably just patch systemd to ignore /nix/store (which obviously cannot be unmounted because systemd is running from it). It already ignores / and /usr:

                /* Skip / and /usr since we cannot unmount that
                 * anyway, since we are running from it. They have
                 * already been remounted ro. */
                if (path_equal(m->path, "/")
#ifndef HAVE_SPLIT_USR
                    || path_equal(m->path, "/usr")
#endif
                )
                        continue;

[viric]

On Fri, Apr 12, 2013 at 03:31:21AM -0700, Eelco Dolstra wrote:

We should probably just patch systemd to ignore /nix/store (which obviously cannot be unmounted because systemd is running from it). It already ignores / and /usr:

Ah so they are mounted ro already, at that point?

[edolstra]

Yes. However, remounting ro might not work correctly if people have /nix/store as a separate filesystem and nix.readOnlyStore enabled (since systemd won't be able to remount the underlying mount point).

[CMCDragonkai]

@edolstra Does still happen? Because I'm seeing this error too: NixOS/nixpkgs#3280

Maybe the fix is only in the master branch?