Guest suspended with DiskFull error when using fixed size VDI

[RP15873]

VirtualBox guest with fixed size VDI file is suspended when the host runs low on disk space. Fixed size VDI files should never trigger a disk full condition as they are a fixed preallocated size that will never expand.

VirtualBox build 146314 Host: Fedora Linux 33 Guest Fedora Linux 34 Log File Info: VD#1: Host disk full VM: Raising runtime error 'DrvVD_DISKFULL' (fFlags=0x6) Console: VM runtime error: fatal=false, errorID=DrvVD_DISKFULL message="Host system reported disk full. VM execution is suspended. You can resume after freeing some space"

VBoxManage showmediuminfo disk ... Storage format: VDI Format variant: fixed default Capacity: 66560 MBytes Size on disk: 66562 MBytes

[aeichner]

What filesystem is your VDI on? "Modern" COW filesystems like btrfs might still run into out of disk space issues even when writing to a fixed size file.