My linode appears to have gone read-only.
Attempting to remount it reveals this:

Avaria ~ # mount -o remount /
mount: block device /dev/ubda is write-protected, mounting read-only

What's happened and have you any prospect on resolving the issue?

I confirm the above post, same problem with my linode on same host. After rebooting it, it is back r/w however.

Yes, I noticed that too - I had to try something since no admin bothered to reply

To report a problem in the future, please use the Support Ticket system.

https://www.linode.com/support/tickets.cfm

Thanks,
-Chris

My apologies I thought the forum and the ticketing system were both as well as each other a place. I shall keep it in mind!