Can't spawn some VMs with a SATA HDD controller when the VDI file is on a btrfs partition

[rocko]

VirtualBox can't spawn some VMs if both these conditions are true:

• the HDD storage controller is set to SATA, and
• the VDI file is on a btrfs partition.

VBox shows a window saying "Spawning..." and later another box appears saying "Spawning (20%)... 2/2". Neither box ever disappears (their processes must be killed).

An example error in the log is:

00:00:00.733 AioMgr0-N: Request 0x000000018b0df0 failed with rc=VERR_INVALID_PARAMETER, migrating endpoint /vbox/maverick32-2.vdi to failsafe manager.

Note however that some VDI files do load successfully from the btrfs partition using the SATA controller.

Workaround are:

• Moving the VDI file to an ext4 partition fixes the problem.
• Changing the storage type for the HDD to IDE instead of SATA also fixes the problem (ie even if the VDI file is on the btrfs partition).

Version info:

VirtualBox: 3.2.2-62298~Ubuntu~lucid Host: Ubuntu 10.04, kernel 2.6.34-generic or 2.6.35-rc1-generic

[rocko]

VBox.log file

[Longinus00]

This happens if "use host I/O cache" is disabled. It is disabled on default for the sata controller but disabled by default for the ide controller. This explains the confusion in the original bug report.

[Longinus00]

I mean, of course, to say that it is enabled by default for the ide controller.

[rocko]

OK, I can confirm that's correct. So the conditions to reproduce this are:

(a) the VDI file on btrfs partition, and (b) use host I/O controller is not set

Is this bug already reported elsewhere?