OpenCV is an open-source Computer Vision library which can be used in Python. Installing OpenCV in MacOS is a bit cumbersome since there is no binaries provided in the website, but you can do this easily with the help of Anaconda. This is what I can share with you to install OpenCV with Anaconda:
Open terminal, and type: conda create –name ComputerVision python=3.7
Ever since I moved my study desk to a different room at home, I had been experiencing very slow wifi connection on my MacBook. This happened only when I attached an external monitor via DisplayPort-to-USB-C converter. Wifi shows it is still connected, but speed can suddenly drop to near-zero rate.
Each time I unplugged the dongle, the problem disappeared. The USB-C dongle seems to generate some signal interference right into MacBook’s wifi antenna.
After hours of frustration, I found out the solution on an internet forum: aluminium foil. It might sound silly, but aluminium blocks radio signal pretty well. Wrap the USB-C dongle with few layers of aluminium foil and the wifi problem is gone.
Interesting that this only happens on MacBook. Other devices do not suffer from the same symptom.
To support our clients, my company uses Citrix XenServer hypervisor quite heavily – because it is simple and it works well. But few days ago, the moment I have dreaded for long time eventually happened: one of our servers refused to boot after a power interruption. No error message shown, it simply wouldn’t boot. I couldn’t even get into the configuration screen.
After many days of looking for a solution, the answer was simple: use the XenServer installation CD/DVD media to reinstall or upgrade the existing XenServer. Sounds risky because that means overwriting many existing files, but it works. This is the step-by-step:
1. Boot machine with XenServer CD/DVD media, enter the installation screen. Stop at the first welcome screen.
2. Type “menu.c32”, don’t press Enter.
3. Press Tab when the new screen opens.
4. Add “disable-gpt” in the parameter list of mboot.c32.
5. Continue with the installation and restart the machine.
This fixes the boot problem while preserving the existing VMs inside. I hope this can be useful for those who may face the same problem.