Tuesday, December 22, 2020

Microsoft Certified: Azure Security Engineer Associate

 Passed AZ-500 today!!

Friday, June 12, 2020

Hyper-V Nested VM

To allow your VM to run Hyper-V role, you need to expose the virtualization extension to the Hyper-V host by running the following PowerShell command:

> Set-VMProcessor -VMname MyVM -ExposeVirtualizationExtensions $true

Friday, May 15, 2020

My QNAP TS-412 had a major issue, 2 of the RAID5 disks decided to fail at the same time. Luckily QNAP was still up and running and allow READ-ONLY access to my data. However, all the iSCSI LUNs are not accessible anymore from my iSCSI clients.

Found the attached document which basically helped me recover my iSCSI LUNs. I copied by iSCSI LUN files to the backup locations and rebuild by NAS volumes. I then follow the procedure #3 in the document to get my iSCSI LUNs back.

Wednesday, April 15, 2020

Ubuntu DNS Stub Listener #Disable

During setting up PiHole, it requires to listen on DNS (53/TCP, 53/UDP) on the host. Ubuntu version that I am running on (20.04) by default listens on port 53 because it runs as DNS Stub Listener.

PiHole will give errors about Binding error

To disable Ubuntu running as DNS Stub Listener, do the followings:

> sudo vi /etc/systemd/resolved.conf 

un-comment #DNSStubListener=yes 
change it to DNSStubListener=no

> sudo service systemd-resolved restart
> sudo systemctl disable systemd-resolved.service
> sudo systemctl stop systemd-resolved
> sudo mv /etc/resolv.conf /etc/resolv.conf.old
> sudo shutdown -h now -r

Monday, March 02, 2020

Wednesday, January 08, 2020

PowerShell and Excel

I wrote a PowerShell script to start MS Excel process and manipulate an Excel file. This PS works perfectly fine when it is executed interactively by a user account. However when using Windows task scheduler, it throws the following errors:

Microsoft Excel cannot access the file
There are several possible reasons:
The file name or path does not exist.
The file is being used by another program.
The workbook you are trying to save has the same name as a currently open workbook.

In turns out, I need to create a directory named: Desktop
In the following locations:

64-Bit OS

32-Bit OS