MGA2 x86_64, Gnome Nvidia graphics, latest proprietary driver from the MGA non-free repo All updates.
1. Gnome starts new session out of the blue Today I was editing a document in gedit. Other open applications were chromium-browser and gkrellm. Suddenly out of the blue in the middle of writing a word the screen changed to a new session, screen with GDM showing). Logging in again no application was saved, work lost as well as 2 tabs in the browser where I did not save the URLs yet. syslog shows a Gnome session I/O failure before the session switch: - Jul 6 07:28:49 marvin-1 gnome-session[2301]: Gdk-WARNING: gnome-session: Fatal IO error 11 (ressource temporarily not available) on X server :0. After session restart a long list of "DEBUG" messages followed. No errors reported in that list. 2. Occasional system deep freeze Starting some time ago and occurring last time yesterday I get a deep freeze (only SysRq keys for forced reboot working). Inquiring I found this message in syslog: - Jul 5 13:27:42 marvin-1 kernel: [10565.322087] NVRM: GPU at 0000:01:00.0 has fallen off the bus. man-draker in the German forum pointed me to http://www.cyberciti.biz/faq/debian-ubuntu-rhel-fedora-linux-nvidia-nvrm-gpu-fallen-off-bus/ which talks about persistence mode of nvidia-smi. The persistence mode is disabled by default. Switched it to "enabled" but I am not sure if this is the true culprit - the same error should have come up more often and on other people's machines as well if this setting was the culprit, right? Another idea was offered by doktor5000: "It could be some malfunction of systemd and you could ask Colin about it". :) Additional information: the freeze is not caused by faulty memory, I let memtest run over nicht for 8 hours, no errors.
