I know this problem is common, but I've gone through all the steps detailed in the other cases, checked the X folder for backups, reinstalled prtools, etc... I just can't figure it out! I'm running on a 2013 rMBP.
Note that the 800x600 resolution comes from the framebuffer setting in Grub. I suspect Parallels Tools allows dynamic resizing by talking to the vesa framebuffer driver in the kernel. If the KB article mentioned above doesn't work, you can set a new framebuffer mode, by adding: GRUB_GFXMODE=1024x768x32 GRUB_GFXPAYLOAD_LINUX=keep to /etc/default/grub and then running: grub-mkconfig -o /boot/grub/grub.cfg This will boot to 1024x768 with 32-bit color. Xorg will then start in 1024x768 resolution.
I've installed, re-installed, and upgraded my Parallels Tools to no avail. I only get 800x600. When I drag to make it larger, it only scales the 800x600 view to a new size. It does not increase the resolution. I'm pretty sure the tools intend to increase the resolution via the frame buffer driver when the window is resized, but that's definitely not working for me in Ubuntu 14.04. Setting the resolution in the grub config is the only solution I could find that actually works.
This worked for me after I installed Ubuntu 15.10 Wily Werewolf inside Parallels for Mac 9.0 http://linuxbsdos.com/2014/10/31/so...solution-in-ubuntu-14-0414-10-and-virtualbox/
Thanks, It solved this issue for me: I had same bug in Ubuntu 14 on Mac OS El Cap, only 800x600 resolution was available and no sharing folders connected after attempt of installing PT from GUI.
