Just a quick post about getting I/O and disk errors on a CentOS 6 VM running in Azure.
I created said VM, did a yum update and then rebooted the VM,
Once it was back up I then started to get lots of I/O errors reported and the file systems were mounted read-only.
After a bit of trial and error plus some web searching I came across this article which had a solution that worked.
I basically Deleted the VM. Then deleted the Cloud Service associated with the VM. Finally I re-created the VM with the same details from the un-attached disk from the original VM (My Disks part of the Gallery).
Now the file systems are mounted correctly and there are no more IO error messages.