mjhjmtu

OS Ubuntu '16.04.5 LTS'

Hypervisor Xen

This output is when sda

 df -h
 Filesystem Size Used Avail Use% Mounted on
 udev 16G 4.0K 16G 1% /dev
 tmpfs 3.2G 1.3M 3.2G 1% /run
 /dev/sda1 792G 9.7G 742G 2% /
 none 4.0K 0 4.0K 0% /sys/fs/cgroup
 none 5.0M 0 5.0M 0% /run/lock
 none 16G 144K 16G 1% /run/shm
 none 100M 32K 100M 1% /run/user

When xvda

 Filesystem Size Used Avail Use% Mounted on
 udev 16G 4.0K 16G 1% /dev
 tmpfs 3.2G 1.3M 3.2G 1% /run
 /dev/xvda1 792G 32G 721G 5% /
 none 4.0K 0 4.0K 0% /sys/fs/cgroup
 none 5.0M 0 5.0M 0% /run/lock
 none 16G 144K 16G 1% /run/shm
 none 100M 32K 100M 1% /run/user
 none 16G 1.3M 16G 1% /tmp/guest-9tjKZL

After Multiple reboots it will comeup with xvda,

I can find these messages in syslogs file

Oct 25 18:43:00 abcd kernel: [ 0.000000] Hypervisor detected: Xen HVM
Oct 25 18:43:00 abcd kernel: [ 0.000000] Xen version 4.1.
Oct 25 18:43:00 abcd kernel: [ 0.000000] Xen Platform PCI: I/O protocol version 1
Oct 25 18:43:00 abcd kernel: [ 0.000000] Netfront and the Xen platform PCI driver have been compiled for this kernel: unplug emulated NICs.
Oct 25 18:43:00 abcd kernel: [ 0.000000] Blkfront and the Xen platform PCI driver have been compiled for this kernel: unplug emulated disks.
Oct 25 18:43:00 abcd kernel: [ 0.000000] You might have to change the root device
Oct 25 18:43:00 abcd kernel: [ 0.000000] from /dev/hd[a-d] to /dev/xvd[a-d]
Oct 25 18:43:00 abcd kernel: [ 0.000000] in your root= kernel command line option
Oct 25 18:43:00 abcd kernel: [ 0.000000] HVMOP_pagetable_dying not supported