Direct Hard Drive Access issues.

Discussions related to using VirtualBox on Linux hosts.
Post Reply
megamoix
Posts: 1
Joined: 24. Jul 2009, 14:29
Primary OS: Ubuntu other
VBox Version: VirtualBox+Oracle ExtPack
Guest OSses: CLFS

Direct Hard Drive Access issues.

Post by megamoix »

Hi all,
First time post for me!

Host Ubuntu Jaunty Desktop + VB 3.0.2 + Hard disk pass through (VBoxManage internalcommands createrawvmdk -filename PATHTO/sdc.vdi -rawdisk /dev/sdc -register)
(ICH6 SATA mode selected under VB)

For some week I am trying to make up and running a CLFS.
Until the system is quite usable, I use to boot it under VB cause it is more convenient.

But I met some very strange issues and I am not sure I clearly understand what happens...

Sometime for convenience I boot off the VM, mount the partition, do some configuration files modifications, build some stuff under chroot, ects...
Then I unmount this partition and boot up again the CLFS system to see how run this modifications.
But weird ! => The state of the file system is like if none of my modifications as been flush to disk by my host!!!
At the beginning I was thinking the root cause came from my use of mount/umount on the host that do not flush for some reasons my modification on the file system (ext3).
But with a full reboot of the host, I am able to get the modification on the VM!
So is there a read caching somewhere (under the Host or under VB) that make my VM to see the old FS and not re read the Physical Hard Disk?

As actually the VM is not able to see the update on the FS if I do some modifications on the VM it show a lots of ext3 errors...
And after few mount/unmout on the host and boot/halt of the VM, the file system end up destroy (and fsck can not recover it)
So then I finish very happy to restart my CLFS build starting with a mkfs.ext3...

Of course I am clear on the fact that this ext3 file system is mounted only in one place at a time (Host or VM)

Thanks in advance.
Mickael.
Post Reply