Categories
Hardware Windows

Fix: Flickering monitors on Lenovo P15

I am currently using a Lenovo P15 laptop, the machine itself is very powerful but has a very annoying isse. When using external monitors, either via docking or directly connected. They will often flicker/disconnect around once per minute. Causing everything to jump around until Windows settles down again. In some cases, the monitors even have to be disconnected and reconnected again before Windows can use them again.

Luckily, this issue can be solved rather easily. In Windows services, find the service named “FirmwareSwitchService”, stop & disable it. If you lack admin permissions, ask your IT department to help you. As there are currently no other ways around this issue on P15 models.

Categories
Hardware Linux Windows

KVM: Optimizing performance on virtual machines (VM`s)

After having set up quite a few VM`s in my career, i have picked up a couple of tips on how to get the most power out of your VM`s:

Get new/correct drivers for your VM`s
Remember to make sure that you have all the correct drivers, this is at least important for IO(Disk) and Network devices. Windows has many devices that will work with basic Microsoft drivers, but that does not mean that the performance magically gets awesome. After making sure that the correct drivers were in place, i managed to go from ~900Mbit to 9.9Gbit on a 10gbit-network between a Linux (Red Hat) and Windows 2k8 server. (tested with iperf which exists for both Windows and Linux)

Turn off Power saving options in BIOS / Hardware
More or less all servers, either they being brick servers, home servers or blade servers, have BIOS settings that enables or disables power saving mode. I know from experience that at least all HP blades comes with power saving enabled per default. Turn off this to make sure that your VM`s gets the performance they expect to get. (I have had VM`s simply be sluggish with this feature turned on, turning it off made CPU-performance get normal)

Turn off CPU throttling on the VM host machine
I have also had issues with slow VM`s even when the power options was fixed in BIOS. I then realized that some Linux distributions (Ubuntu) have a default CPU scheduler that throttles down the CPU when it is not needed. After making sure that the host did NOT do this, the VM`s finally started acting as they should. Check out your Linux distributions guides on how to change this.

 

Any other tips i should add to the list? Feel free to add a comment below! ūüôā

Categories
Hardware

HP iLO: Controller firmware revision 2.07.00 Embedded media manager failed initialization

I just¬†received¬†a notice during boot of a HP G8 server regarding iLO¬†issues: “iLO 4 has detected a self test error. For details consult the iLO¬†4 server and iLO¬†4 diagnostics page”.

Went into the iLO diagnostics page (in the¬†Blade Center¬†admin) and found the error message “Controller firmware revision 2.07.00 Embedded media manager failed initialization”. Google does not give too much info regarding this, so it is a bit hard to see what is going on regarding this. I tried to restart both the blade and the iLO itself, but the error did not go away.

I had to contact HP regarding this, and the conclusion(after both having to try a firmware upgrade and firmware re install), was that it was a hardware error on the iLO storage, so HP had to replace the whole motherboard for that server.

Categories
Hardware

Xerox ColorQube error code 001-535

New rounds with problems on a Xerox ColorQube, this time i was greeted with error code “001-535”. This “translates” to problems with the power supply.This was not resolved until a technician came on site with a new power supply to replace the old one.

Categories
Hardware

Xerox-printer giving error code 016-799

Just figured out that some Xerox-printers when getting a job with a unknown paper format or other strange settings. The printer will simply return the error code 016-799.

The only solution i has found for this so far is to make sure that the print jobs actually have a paper format that the printer supports. (And of course, no other strange settings…)

Pdf-files for example can in some cases have print settings embedded, so it is extra smart to check those before printing them.