Bug 438271

Summary:	Plasma wayland: Only black screen with cursor when using NFS $HOME mounted with sec=krb5i
Product:	[Plasma] plasmashell	Reporter:	Stefan <sstaeglich>
Component:	general	Assignee:	David Edmundson <kde>
Status:	RESOLVED NOT A BUG
Severity:	crash	CC:	nate, p.r.worrall, plasma-bugs-null
Priority:	NOR	Keywords:	wayland-only
Version First Reported In:	5.22.0
Target Milestone:	1.0
Platform:	Neon
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Stefan 2021-06-08 16:40:44 UTC

SUMMARY
Only a black screen with cursor is shown if the home directory is stored on a NFS file server

STEPS TO REPRODUCE
1. Mount a NFS share as home directory
2. In SDDM chose plasma wayland session
3. Login

OBSERVED RESULT
Only a black screen with cursor is shown

EXPECTED RESULT
Plasma starts and is usable

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: KDE neon 5.22 User Edition
(available in About System)
KDE Plasma Version: 5.22.0
KDE Frameworks Version: 5.82.0
Qt Version: 5.15.3

ADDITIONAL INFORMATION
I've tried this in different setups (GPU type, hardware, plasma version ....). Only the home directory (local or NFS made a difference).

Comment 1 Paul Worrall 2021-06-15 17:23:40 UTC

I have my home directory on an NFS server and can use Plasma on Wayland OK.  My software versions are the same, except I've got Frameworks 5.83.0, not likely to be that though.

Can you switch to a terminal (e.g. Ctrl-Alt-F2) and log in that way?

Comment 2 Stefan 2021-06-15 20:09:03 UTC

@Paul Starting it on terminal via startplasma-wayland doesn't make a difference. Can you describe your setup in more detail (e.g. NFS version, linux distribution, mount options)?

In my current setup it's NFS 4.2 with sec=krb5i and cachefilesd. I'll try it with sec=sys and without cachefilesd again.

Comment 3 Paul Worrall 2021-06-15 21:50:05 UTC

@Stefan I'm using KDE Neon user edition, updated today.
My fstab entry is:
192.168.0.2:homes /home nfs defaults 0 0

And the exports file on the server has:
/srv/nfs4       192.168.0.0/24(rw,async,fsid=root,crossmnt,no_subtree_check)
/srv/nfs4/homes 192.168.0.0/24(rw,async,no_subtree_check,no_root_squash)

nfsstat -m says version is 4.2
cachefilesd is not installed and I'm not using kerberos

Comment 4 Stefan 2021-06-17 17:12:04 UTC

Ok I'm quite sure that I made other experiences in past: But now I can get plasma wayland running when I disable the use of kerberos (sec=sys).

This makes sense somehow because I made similar experiences with Ubuntu snap packages.

Comment 5 Stefan 2021-06-21 15:47:53 UTC

There was still a statement "export KWIN_DRM_USE_EGL_STREAMS=1" in $HOME/.profile (there is still a /etc/profile.d/kwin.sh). After removing the statement plasma-wayland is starting. But the performance and stability is horrible (nvidia GPU).

Comment 6 Nate Graham 2022-01-12 16:13:48 UTC

Thanks, looks like this was caused by a setup problem, so nothing for Plasma to do. :)