this is something virtio related for sure, a bug or similar. (doesn't hurt to do qemu-img info <volume-name> to ensure it's virtual size is indeed still 200GB and that it has not been resized)
(In past, I've seen tons of issues with VirtIO drivers in Windows 2008/2012 guests - under load, BSOD, network disconnections etc) So I would advise researching similar bugs on google and possibly updating VirtIO drivers. Best, On Wed, 16 Sep 2020 at 18:34, Volodymyr Melnyk <[email protected]> wrote: > Hello, > > To be exact, this matter doesn't seem to be ACS-related, it's rather > VirtIO-related, though I'd like to post this message just to see if > anyone else faced the same. > > There were 3 or 4 times when I encountered the following glitch > glitch: a guest operating system (it happened only to Windows Server > guests, I never saw it with Linux guest) "decides" that its primary disk > storage has more size than it actually is. > > For example, an instance had a virtual drive of 200 GB, it had been > worked fine for years, but at some moment (no one knows at which exactly > one) primary partition (we mean "drive C:", which usually is the 2nd > one, as the 1st one is being used by the operating system) became the > size of ~210 GB just out of the blue. After that, the system event log > started growing with the following error messages: `The driver detected > a controller error \ Device \ Harddisk0 \ DR`. Perhaps, it happens when > the operating system tries to write pieces of data to the sectors that > don't exist. > > Once I expand this virtual drive to 210 GB, the error messages don't > appear anymore. Still, after that I find some part of the data > corrupted (maybe some fragments of files are being stored to the > non-existent sectors), so it seems to be a real problem when it happens. > > Alas, I didn't find a way to reproduce that. As I stated before, it's > happened only 3-4 times (the first occurrence was ~2 years ago) in the > environment of >1000 VMs, so the glitch is rare, though each time the > outcomes are quite unpleasant. :-/ > > Just curious, did anyone saw something similar? > > Thanks in advance for any comments. > > -- Andrija Panić
