Allow Linux VM running on KVM paravirtualized environment to support disk hotplugging

In case you have a Linux OS VM running on KVM paravirtualized environment and found that it doesn't response to the new virtual disk you added (you dont see a new disk on dmesg or nothing coming up from fdisk -l), you will need to make sure virtio_blk driver is in place.


[root@vm ~]# lsmod | grep -i virtio
virtio_net             15665  0
virtio_balloon          4281  0
virtio_blk              5087  3
virtio_pci              6733  0
virtio_ring             7169  4 virtio_net,virtio_balloon,virtio_blk,virtio_pci
virtio                  4824  4 virtio_net,virtio_balloon,virtio_blk,virtio_pci


Indeed, you should be seeing /dev/vd* instead of /dev/sd* if you have picked correct OS type during VM initialization. In case you are seeing /dev/sd*, probably you didnt pick correct OS type and that caused virtio associated driver not being loaded.

[root@vm ~]# fdisk -l /dev/vda

Disk /dev/vda: 21.5 GB, 21474836480 bytes
16 heads, 63 sectors/track, 41610 cylinders
Units = cylinders of 1008 * 512 = 516096 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0006fe0a

   Device Boot      Start         End      Blocks   Id  System
/dev/vda1   *           3         409      204800   83  Linux
Partition 1 does not end on cylinder boundary.
/dev/vda2             409       41611    20765696   8e  Linux LVM
Partition 2 does not end on cylinder boundary.