Yesterday I posted a desperate plea for help as I had no idea where else to look for clues on what was causing random I/O errors on the guests of our jessie KVM host.

Thanks to Michael Herold, who was kind enough to mail me after identifying our problem, now we know os-prober is to blame, triggering the problem on every kernel update on the host, and we have quickly uninstalled it from all our systems.

Thanks Michael! If you by any chance going to attend FOSDEM, I am so happily going to buy you beers!

Let's hope anyone else wondering what's going on with their filesystems will find the trail to these blog posts to find a quick solution!