I've searched through existing questions, but nothing addresses my problem.

My system running Ubuntu 14.04 went through a partial-update a few days ago. Ever since, my system will not boot. It freezes on the purple screen. (plymouth?) When I attempt to boot to recovery, I get a "gave up waiting for root" error along with numerous libkmod errors.

I've booted from a liveCD and attempted some troubleshooting. I can mount the root partition from there and chroot over. I checked /var/log/boot and found 2 small failures - samba and ksplice - nothing that should prevent booting. I tried to reinstall grub with the following, after mounting the boot partition to /boot:

```
sudo grub-install --efi-directory=/boot /dev/sdc

```

Unfortunately, this produces the same libkmod errors that appear when I try to get to recovery. (I do have an efi, not BIOS)

Here's what recovery ends with:

```
Gave up waiting for root device. Common problems: 
- Boot args (cat /proc/cmdline) 
- Check rootdelay= (did the system wait long enough?) 
- Check root= (did the system wait for the right device?) 
- Missing modules (cat /proc/modules; Is /dev) 
ALERT! /dev/mapper/ubuntu--vg-root does not exist. Dropping to a shell! 
libkmod: ERROR ../libkmod/libkmod-config.c:686 kmod_config_parse: /etc/modprobe.d/zfs.conf line 2: ignoring bad line starting with '#' 
libkmod: ERROR ../libkmod/libkmod-config.c:686 kmod_config_parse: /etc/modprobe.d/zfs.conf line 3: ignoring bad line starting with '#' 
libkmod: ERROR ../libkmod/libkmod-config.c:686 kmod_config_parse: /etc/modprobe.d/zfs.conf line 4: ignoring bad line starting with '#' 
libkmod: ERROR ../libkmod/libkmod-config.c:686 kmod_config_parse: /etc/modprobe.d/zfs.conf line 5: ignoring bad line starting with '#'
libkmod: ERROR ../libkmod/libkmod-config.c:686 kmod_config_parse: /etc/modprobe.d/zfs.conf line 2: ignoring bad line starting with '#' 
libkmod: ERROR ../libkmod/libkmod-config.c:686 kmod_config_parse: /etc/modprobe.d/zfs.conf line 3: ignoring bad line starting with '#' 
libkmod: ERROR ../libkmod/libkmod-config.c:686 kmod_config_parse: /etc/modprobe.d/zfs.conf line 4: ignoring bad line starting with '#' 
libkmod: ERROR ../libkmod/libkmod-config.c:686 kmod_config_parse: /etc/modprobe.d/zfs.conf line 5: ignoring bad line starting with '#'
libkmod: ERROR ../libkmod/libkmod-config.c:686 kmod_config_parse: /etc/modprobe.d/zfs.conf line 2: ignoring bad line starting with '#' 
libkmod: ERROR ../libkmod/libkmod-config.c:686 kmod_config_parse: /etc/modprobe.d/zfs.conf line 3: ignoring bad line starting with '#' 
libkmod: ERROR ../libkmod/libkmod-config.c:686 kmod_config_parse: /etc/modprobe.d/zfs.conf line 4: ignoring bad line starting with '#' 
libkmod: ERROR ../libkmod/libkmod-config.c:686 kmod_config_parse: /etc/modprobe.d/zfs.conf line 5: ignoring bad line starting with '#'

```

I have ZFS installed, but the boot drive is not ZFS. I don't understand why commented out lines would be interpreted as bad.

Here's my fstab:

```
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
/dev/mapper/ubuntu--vg-root /               ext4    errors=remount-ro 0       1
# /boot was on /dev/sdb2 during installation
UUID=10d83bf1-14a9-40bf-8ada-7ffbf6220bf9 /boot           ext2    defaults
  0       2
# /boot/efi was on /dev/sdb1 during installation
UUID=BD9B-EA73  /boot/efi       vfat    defaults        0       1
/dev/mapper/ubuntu--vg-swap_1 none            swap    sw              0       0

```

And parted info for my boot drive:

```
Model: ATA Corsair CSSD-V32 (scsi)
Disk /dev/sdc: 32.0GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt

Number  Start   End     Size    File system  Name  Flags
 1      1049kB  538MB   537MB   fat32              boot
 2      538MB   794MB   256MB   ext2
 3      794MB   32.0GB  31.2GB                     lvm

```

I have no other OSes installed. I've tried to reinstall from the liveCD, but it does not recognize my existing install - even after I mount my root partition manually. I would prefer to avoid re-installing from scratch, and would really like to learn what is causing this for my own Linux knowledge betterment. Any help would be greatly appreciated.