This issue was very strange.
Symptoms:
- The pool would disappear from the system some minutes after booting up.
- Restarting the bus driver would make the pool reappear, only to disappear some minutes later.
Observations:
- The mount process was completely functional, since the pool was accessible prior to disappearing.
- The virtual disk was being created properly and was still listed in disk management, even after the drive disappears in explorer.
- After the pool disappears, in disk management, the pool volume was being listed as "GPT Protective Partition". This normally happens when the GPT itself is corrupt.
Conclusions:
- Some time after the pool is mounted, the GPT is overwritten by something running in the system.
- Refreshing the disk management page seems to trigger this, so I suspect that VDS itself is overwriting the disk and making it unusable.
Fix:
- Make the emulated physical disk read only in order to prevent the MBR / VBR from being overwritten and damaged.
- [D] [Issue #15604] Make the emulated physical disk read-only in order to prevent malicious software from overwriting it causing the pool to be inaccessible.
In the process of investigating this, I converted the pool to a MBR disk, but that didn't fix the problem.
Almost certainly this is a software issue, and not a hardware issue. Some rogue piece of software, or a corruption of the OS itself is damaging the pool after some time.