My problem is kinda messy, so I thank you in advance for reading through this...
I own a HP ZBook 17 G2 with a dual boot Windows 10/Linux Mint 17.3. I've had no problem so far, but suddenly this morning I wasn't able to boot into my Linux Mint anymore (but still could boot into Linux). The only thing I got was a black screen, so I got into recovery mode to try to hopefully have some more information. I apologize because my memory is a bit vague, but I seem to remember at least one (of possibly many) worrying message saying something like "Failed to load /boot/efi, press ... etc etc".
Not knowing what to do, I booted my "boot-repair-disk" USB Live key, and let it do its usual thing (which saved me a couple of times in the past). I should mention that "boot-repair" had me typing a couple of commands in the terminal during the procedure, which seemed quite unusual to me... In any case, here is the "boot-repair" report : http://paste.ubuntu.com/25989656/ . A few things about the various paritions that appear in the report :
_ sda1 is Windows Recovery partition that I've had for a while, and came with the installation of Win10
_ sda2 is my "EFI" partition as far as I understand
_ not sure what this sda3 partition is, but I think it has been here for a while
_ sda4 is my Win10 partition
_ sda5 : this one is weird : it's a ntfs partition about ~1GB big, but I don't remember it being around... and it has those weird flags (like "hidden") ; but it might be completely unrelated to my current problem...
_ sda6 is my Linux Mint partition
_ sda7 is my swap partition
_ sdbXX are partition from a second hard drive I installed a couple months ago, which actually is a hard drive from a older laptop ; it also contains several partitions, as I had a dual boot on that laptop
_ sdc1 is just my USB stick
This first "boot-repair" didn't solve the problem (still couldn't boot), but it changed a few things : I got ton of new entries in my Grub at startup (starting like "/EFI/ubuntu/....." and "/EFI/HP/...." ones), and the error messages at boot became different, something like this :
which then brings me to this BusyBox shell....Gave up waiting for root device. Common problem :
- Boot args ....
- Check rootdelay ....
- missing modules ...
ALERT! /dev/disk/by-uuid/<big-serial-number> does not exist. Dropping to a shell !
I thought for a second that the problem might be somehow related to my second hard drive being there, and having all those partitions inside, so I removed it and reran "boot-repair", and got the following report : http://paste.ubuntu.com/25989722/
But still, no luck with my problem, I still got the errors and still couldn't boot...
One last thing : interestingly enough, after exploring, and choosing the "Advances options for Linux Mint" in my Grub, I noticed that I could boot two different kernels, which I don't think (again, fuzzy memory...) was not the case at the very beginning of this ordeal... Might have been the result of one of the command that "boot-repair" made me type ! In any case, here are the two kernel options I got :
_ Linux 3.19.0-32-generic
_ Linux 3.13.0-135-generic
So the first one is the default one that I cannot boot in... but surprisingly I can boot into the second one ! After a couple of minutes of checking, everything seems to work fine... except that I cannot access internet :-/ I tested both Wi-fi and ethernet, the laptop appears to connect to my router just fine, but I cannot reach any webpage...
And here I am, out of ideas... Thanks in advance for your help !