Windows guests on Linux 64-bit host freezes intermittently

[steveatoracle]

I have an Oracle Linux 5.6 Linux 64-bit host with VirtualBox 4.1.8 The host details: 16 cores 140 GB ram Disc controller: Raid,etc. 1 - 1GB Ethernet connection (motherboard NIC)

Currently, I have 5 VM guests, 3 Windows 2008 64-bit and 2 OL 5.6 64-bit

The host is not heavily utilized at this point.

What I am seeing is in the Windows Guest OS (accessed via Remote Desktop), if I do any type of activity the requires networking (i.e. Open FireFox, copy files to a mapped network share, etc.), then I see the CPU for that particular VM spike to 100%+ for a period of time (it varies but 1-3 minutes) and the guest is unresponsive (I have tested Remote Desktop and directly via the console).

The Windows Guest are bridged using Adapter 1: Intel PRO/1000 MT Server (Bridged adapter, eth1)

On the Linux Guest, I see similar, but the cpu spikes quickly and then drops within seconds.

I am not sure if the guest's are having a network contention issue on the host.

Each VM has a unique network MAC / hardware address

I am using the native VirtualBox Intel NICs

I see this behavior on a second Linux host with VirtualBox 4.1.6 as well and Windows 7 65-bit guests.

I have attached the VM log, I can provide whatever further debugging you require.

[steveatoracle]

Vbox.log

[Frank Mehnert]

Known issue of the ICH9 chipset emulation. Please change it to PIIX3 in the VM settings, the ICH9 emulation isn't stable.