Ticket #965 (closed defect: invalid)
full CPU usage when raw disk is attached
|Reported by:||privateer||Owned by:|
|Version:||VirtualBox 1.5.2||Keywords:||raw disk full load 100% 50% CPU|
I've started experimenting with the new feature of using raw disk with vbox. I'm stuck with virtual machine using 50% CPU (one core) right on boot - i.e. in GRUB, any OS booted from mentioned drive, CD or whatever. It is stable but slow. It just takes one CPU core for it's own - no matter what. At the same time disk image-files performs excellent with low load.
I know that using raw disks is somehow experimental yet. I did RTFM though and I found nothing about such performance drop. Manual even says: "it allows a guest operating system to access its virtual hard disk much more quickly than with disk images" - which is to be expected.
Therefore I guess it deserves a ticket to support you on your great work.
Some details: I'm using VirtualBox 1.5.2r25433 (closed source version as open src doesn't have mentioned feature :| )
The vmdk file has been created with following command: VBoxManage internalcommands createrawvmdk -filename /media/hda5/virt/raw.vmdk -partitions 1 -rawdisk /dev/sda (I experimented with other partitions too - no change)
My OS is Ubuntu Gutsy # uname -a Linux privateer 2.6.22-14-generic #1 SMP Sun Oct 14 23:05:12 GMT 2007 i686 GNU/Linux
The drive is a regular SATA HDD, nothing fancy.
I have experimented with all ACPI settings combinations of my virtual machine - no change.
Changing the amount of memory from 128 to 512MB doesn't change the thing either.
I found nothing in syslog or vbox log (attached).