This post refers to OS 1.4; this issue has been resolved for all subsequent OS versions.

During internal testing we discovered an issue that might impact Windows Azure Drive (Beta) users under heavy load causing  I/O errors.   All users need to upgrade to OS 1.4 immediately, which has a fix for the problem.

Note, this issue does not apply to Windows Azure Blobs, Tables or Queues.

To ensure that your role is always upgraded to the most recent OS version, you can set the value of the osVersion attribute to “*” in the service configuration element.  Here’s an example of how to specify the most recent OS version for your role.

<ServiceConfiguration serviceName="<service-name>" osVersion="*">
  <Role name="<role-name>">
….
  </Role>
</ServiceConfiguration>

If you would like to upgrade to OS 1.4 without being auto-updated beyond that, you must replace the “*” above and set the value of the osVersion attribute to “WA-GUEST-OS-1.4_201005-01”.

Additional details on configuring operating system versions and the service configuration are available here.

Dinesh Haridas