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SCOTIA SYSTEMS BLOG




Slow Network Performance on new Hyper-V Server

March 2nd, 2013 admin

Having set up a new Hyper-V platform on a powerful new Dell PowerEdge server (plenty of CPU/RAM/Disk) I was dismayed to find the first VM on it performing poorly with respect to network activity?

Everything seemed correct, I checked the integration utilities were installed and drivers were up to date, so what could it be?

This time it turned out to be a setting in the Broadcom NetXtreme Gigabit adapter on the host server.    Once I’d disabled “Virtual Machine Queues” on the host, the VM was flying along again at full speed!

The setting is under the Advanced tab of the device properties as you can see below:

 

virtual-machine-queues





Ethernet Disabled on Linux VM When Duplicated

April 5th, 2011 admin

Here’s a quick tip to start the day!  

I recently found when duplicating a virtual Linux machine using Windows Hyper-v that when the duplicated machine booted, the Ethernet port was disabled?

Watching the boot sequence I saw the following:

Device seth0 has different MAC address than expected, ignoring.

As the new machine has a unique MAC address, the Linux install doesn’t like this and automatically disables the interface!

There’s a quick fix however – you need to edit the file:

/etc/sysconfig/network-scripts/ifcfg-seth0

In this file, change the “HWADDR” entry to match the new MAC address of the virtual network card (you can find this under the settings for the VM).

Finally, restart networking by running :

/etc/init.d/network restart





Setting up Home Automation X10 CM11a

October 21st, 2009 admin

Had a tough time yesterday getting Homeseer (excellent product!) to talk to my CM11a X10 adapter.   If you’ve never seen one of these – it plugs into the mains and talks to the PC via a serial connection.

Simple – you might think!   However, not so simple when Homeseer is running on a virtual 2008 Hype-V machine!

Eventually got it going using a Lantronix EDS4100 serial over ethernet adapter.   The problem that stumped me for a while though – was that the CM11a needs to run at 4800 baud (not the 9600 default of the EDS).   Anyway – all up and running sweetly now 🙂

 

I still have a small issue of problems with Homeseer running as a service on 2008 – but from the Homeseer forums – looks like I’m not the only one with this issue.