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Misc

Openwrt on UAP-AC-PRO

Use as AP

Disable Firewall and dnsmasq:

/etc/init.d/firewall stop
/etc/init.d/firewall disable
opkg remove dnsmasq

UAP-AC-PRO has 2 NICs, "main" nic is LAN, "secondary" nic is WAN

LAN is set to have a static IP of 192.168.1.1, if you want it to show up as a normal AP (get a DHCP address) You'll need to change the "Protocol under LAN interface to DHCP Client

img.gz to sdcard

This will show how to unzip a .gz file, redirect it to dd so you can write a img.gz file to an sdcard without having to unzip it to the filesystem first.

sudo -s -E
dd_if="$HOME/Downloads/LibreELEC-RPi.arm-9.2.6.img.gz" dd_of='/dev/mmcblk0' ; \
  gzip -d -c "${dd_if}" | \
  dd of="${dd_of}" & \
  ddpid=$! ; while [ $(ps -ao pid | grep $ddpid) ]; do kill -SIGUSR1 $ddpid; sleep 3; done

a few things are going on here, lets break it out, line by line. 1. Run as root. 1. Setting environment variables that are used. This allows us to use the same command multiple times, If we want to write something different to a different place, just edit the env vars. 2. use gzip to unzip the img.gz file to stdout. 3. use dd to write the stdout from gzip to "${dd_of}". 4. This is used to check the progress of dd.

Cheap bitcoin node

Item Price Notes
HP t530 Thin client $40 4G of ram and PSU
1tb m.2 sata SSD $36 Used or New, not sure if dram matters
Total $76

Storage speeds

USB

Item Bandwidth Notes
USB 2.0 480Mbps
USB 3.0 5 Gbps
USB 3.1 Gen 1 5 Gbps Hp EliteDesk G3 800 Mini
USB 3.1 Gen 2 10 Gbps
USB 3.2 Gen 1 5 Gbps
USB 3.2 Gen 2 10 Gbps Dell Wyse 5070
USB 4 Gen 2x2 20 Gbps
USB 4 Gen 3x2 40 Gbps

Sources:

  • https://www.techadvisor.com/article/742967/usb-speeds-types-and-features-explained.html

SSDs | HDDs | Connectors

Item Bandwidth Notes
Sata 3.0 6 Gbps Easy to saturate USB 10Gbps
PCI-E Gen3 x 4 32 Gbps
PCI-E Gen4 x 4 64 Gbps

Sources:

  • https://www.kingston.com/en/blog/pc-performance/pcie-gen-4-explained