I have one server, which I did not use for one month, literally shut down.
The server is running Debian 9.0. I upgraded it from Jessie about two months ago to testing repository.
Yesterday I needed it, so I turned it on and upgraded all packages for security reasons.
Before this upgrade: GRUB booted automatically the only OS on this server.
After this upgrade: I must press Enter for it to do so. Therefore I must have keyboard plugged in etc. I am sure you understand the inconvenience.
Also I noticed changed background both on the login screen, and the desktop.
As far as I know, this file:
/etc/default/grub is responsible for GRUB's behavior, so I copy-paste it first:
# If you change this file, run 'update-grub' afterwards to update # /boot/grub/grub.cfg. # For full documentation of the options in this file, see: # info -f grub -n 'Simple configuration' GRUB_DEFAULT=0 GRUB_TIMEOUT=5 GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian` GRUB_CMDLINE_LINUX_DEFAULT="quiet" GRUB_CMDLINE_LINUX="" # Uncomment to enable BadRAM filtering, modify to suit your needs # This works with Linux (no patch required) and with any kernel that obtains # the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...) #GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef" # Uncomment to disable graphical terminal (grub-pc only) #GRUB_TERMINAL=console # The resolution used on graphical terminal # note that you can use only modes which your graphic card supports via VBE # you can see them in real GRUB with the command `vbeinfo' #GRUB_GFXMODE=640x480 # Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux #GRUB_DISABLE_LINUX_UUID=true # Uncomment to disable generation of recovery mode menu entries #GRUB_DISABLE_RECOVERY="true" # Uncomment to get a beep at grub start #GRUB_INIT_TUNE="480 440 1" I did not do any other change. I am unsure whether it upgraded from Stretch to Sid or whatever the naming is. I am also confused as to what could cause this kind of seemingly negligible problem, but I sincerely hope there are folks who understand Debian better than me.
If you need any information I will deliver it on a timely fashion.
EDIT1:
uname -a output
Linux backup-server 4.9.0-1-amd64 #1 SMP Debian 4.9.2-2 (2017-01-12) x86_64 GNU/Linux and
cat /etc/apt/sources.list output
deb http://ftp.sh.cvut.cz/debian/ testing main contrib non-free deb-src http://ftp.sh.cvut.cz/debian/ testing main contrib non-free deb http://security.debian.org/ testing/updates main contrib non-free deb-src http://security.debian.org/ testing/updates main contrib non-free 