Disable IPv6 on Debian

Append the following in the /etc/sysctl.conf file:




net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1
net.ipv6.conf.tun0.disable_ipv6 = 1

and run:

sudo sysctl -p

and reboot

Remove rate limit on pi-hole

Edit /etc/pihole/pihole-FTL.conf

Change RATE_LIMIT line to:

RATE_LIMIT=0/0

then restart pi-hole:

sudo service pihole-FTL restart

You won't see random DNS resolution issues again!

Resizing video using FFMPEG and Nvidia GPU

Recently I had to resize a rather large 4k H.265 video file to 1080p H.265 file. This is what I used. SO much faster than using the CPU for decoding!

ffmpeg.exe -vsync 0 -hwaccel cuda -hwaccel_output_format cuda -i <input file> -resize 1920x1080 -c:v hevc_nvenc -preset fast -rc vbr -acodec copy <output file>

Enable direct P2P ethernet connection between 2 computers (Windows)

I recently had to add a secondary ethernet connection between two PCs, in order to quickly transfer lots of data between them. I ended up using two USB 2.5Gbps network adapters; those computers were already on a Gigabit LAN.

 In order to prioritize the transfer over the 2.5Gbps connection, I had to make a manual entry in each computer's routing table. Let's assume the static IP address of each machine are 192.168.200.1 and 192.168.200.2.

Step 1: You need to run ROUTE PRINT and find the network interface (IF) number of the device. e.g. 49 for our example below

Step 2: Then in an elevated Command prompt, execute the following:

route -p add <destination network> MASK <net mask> <gateway> METRIC <interface metric> IF <interface number>

e.g. On 192.168.200.1 computer: route -p add 192.168.200.0 MASK 255.255.255.0 192.168.200.2 METRIC 1 IF 49

e.g. On 192.168.200.2 computer: route -p add 192.168.200.0 MASK 255.255.255.0 192.168.200.1 METRIC 1 IF 49

Now whenever you initiate network traffic between the two, it will use the direct connection (192.168.200.0 network) you setup, instead of their usual LAN (say 192.168.x.0).

Chia 2.0 GPU plotting performance compilation

Compiled summary of different Nvidia GPU plotting performance from folks on the web, using Chia 2.0.0+ bladebit.

These are across various CPU models and configurations, so use it as a rough guideline to spec your plotter hardware.

In general, 

I will update as I discover more.

GPU	System RAM (GB)	Time (s)
Tesla P4	256	485
GTX 1070	128	286
Tesla P40	256	242
RTX 3050	256	230
RTX 3060 Ti	128	187
RTX 3070	128	167
RTX 4060 Ti	128	162
RTX A4000	256	122
RTX 3070	256	97
RTX A5000	128	90
RTX 3090	256	77
RTX 4090	256	75

How to fix “Authentication is required to create a color profile/managed device” when using xrdp

For those folks getting that annoying message when RDP into a Linux host running xrdp.

Create a new config file here:

$sudo nano /etc/polkit-1/localauthority/50-local.d/45-allow-colord.pkla

and put:

[Allow Colord all Users]
Identity=unix-user:*
Action=org.freedesktop.color-manager.create-device;org.freedesktop.color-manager.create-profile;org.freedesktop.color-manager.delete-device;org.freedesktop.color-manager.delete-profile;org.freedesktop.color-manager.modify-device;org.freedesktop.color-manager.modify-profile
ResultAny=no
ResultInactive=no
ResultActive=yes

Credit: https://devanswe.rs/how-to-fix-authentication-is-required-to-create-a-color-profile-managed-device-on-ubuntu-20-04-20-10/

How to import a virtual machine (in OVA format) into Proxmox server

1.  Download the .ova file in the Proxmox server shell
2. Then do the following:

$ mkdir ova_import

$ cd ova_import

$ tar -xvf ../<filename>.ova

$ sudo qm importovf 101 ./<filename>.ovf <disk> --format qcow2

$ sudo qm importdisk 101 ./<filename>.vmdk <disk> --format qcow2

Then use the Proxmox GUI to attach the disk to the VM, configure Network and you're done!