I attempted to do a logical volume resize yesterday using the follwoing commands

$sudo pvdisplay

  "/dev/sda8" is a new physical volume of "113.11 GiB"
  --- NEW Physical volume ---
  PV Name               /dev/sda8
  VG Name               
  PV Size               113.11 GiB
  Allocatable           NO
  PE Size               0   
  Total PE              0
  Free PE               0
  Allocated PE          0
  PV UUID               jwyO1o-b2ap-CW51-kx7O-kf26-arim-SM8V6m

$sudo vgextend vg /dev/sda8

sudo vgdisplay vg
  --- Volume group ---
  VG Name               vg
  System ID             
  Format                lvm2
  Metadata Areas        2
  Metadata Sequence No  9
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                5
  Open LV               5
  Max PV                0
  Cur PV                2
  Act PV                2
  VG Size               131.74 GiB
  PE Size               4.00 MiB
  Total PE              33725
  Alloc PE / Size       4769 / 18.63 GiB
  Free  PE / Size       28956 / 113.11 GiB
  VG UUID               AhusW2-pzFv-3W32-mpv2-s5VG-FN7S-kVSadx




$sudo lvresize -L +20GB /dev/mapper/vg-var

So as you can see, it looks like adding the physical volume to the vg worked, because i see free space available there. When I typed the lvresize command, it never returned. I let this run overnight in the background, but this morning I still couldnt successfully do a "pvdisplay" or "lvdisplay" because I think it was waiting on a lock or something, so the command never returned.

When i went to log onto the server's console, I saw a bunch of messages like:

rcu_sched_state detected stall on cpu 2

Now when I boot, I get a kernel panic error, and a message about not being able to mount /mapper/vg-root

cannot open root device "mapper/vg-root" or unknown_block(0,0)
Kernel Panic -not syncing: VFS: Unable to mount root file system on unknown_block(0,0)

What should I do to get my system back up and running? Did I attempt to do the logical volume resize correctly?

Thanks