[rdo-list] RDO Mitaka: Kernel panic after instance update - not syncing: VFS: Unable to mount root fs on unknown-block(0, 0)

Hello together, After yum update on CentOS 7.2 instance running on Mitaka, I'm getting the following Kernel panic message: I'm using NFS as storage backend and had a similar problem with CentOS-7-x86_64-GenericCloud-*1608*.qcow2 image and hat to use CentOS-7-x86_64-GenericCloud-*1511*.qcow2 image (which worked fine till now). Has someone faced the same problem with instance updates? By the way, the kernel panic doesn't happen after yum update on a CentOS 7.2 installation on bare metal. Thx! -Arash [ 0.889347] No filesystem could mount root, tried: [ 0.890271] *Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)* [ 0.891813] CPU: 5 PID: 1 Comm: swapper/0 Not tainted 3.10.0-514.2.2.el7.x86_64 #1 [ 0.893287] Hardware name: Fedora Project OpenStack Nova, BIOS seabios-1.7.5-11.el7 04/01/2014 [ 0.894829] ffffffff818b4340 0000000080f55afb ffff8801820dbd60 ffffffff816861cc [ 0.896526] ffff8801820dbde0 ffffffff8167f5d3 ffffffff00000010 ffff8801820dbdf0 [ 0.898204] ffff8801820dbd90 0000000080f55afb 0000000080f55afb ffff8801820dbe00 [ 0.899881] Call Trace: [ 0.900525] [<ffffffff816861cc>] dump_stack+0x19/0x1b [ 0.901420] [<ffffffff8167f5d3>] panic+0xe3/0x1f2 [ 0.902279] [<ffffffff81b0a602>] mount_block_root+0x2a1/0x2b0 [ 0.903234] [<ffffffff81b0a664>] mount_root+0x53/0x56 [ 0.904127] [<ffffffff81b0a7a3>] prepare_namespace+0x13c/0x174 [ 0.905089] [<ffffffff81b0a270>] kernel_init_freeable+0x1f5/0x21c [ 0.906077] [<ffffffff81b099db>] ? initcall_blacklist+0xb0/0xb0 [ 0.907058] [<ffffffff81674630>] ? rest_init+0x80/0x80 [ 0.907944] [<ffffffff8167463e>] kernel_init+0xe/0xf0 [ 0.908844] [<ffffffff81696718>] ret_from_fork+0x58/0x90 [ 0.909769] [<ffffffff81674630>] ? rest_init+0x80/0x80