u/SkySurferSouth

Same as alloyavenue.com or backyardmetalcasting.com (the latter is still available, but not a forum). It appears that the first site is dead no, did they stop activities ?

This furnace is 5kW (3kW should suffice for me) and allows melting 350g (50ml) stainless steel and much more copper alloys. That fits my hobby and it is more efficient than propane melting.

Any ideas on this ?

https://www.amazon.de/-/en/ZenSeFarin-Intermediate-Frequency-Aluminium-Circulation/dp/B0GJ5DL2M7?crid=1BJVE7ZV6WM5U&dib=eyJ2IjoiMSJ9.yl41AnxprPRENsJIbex6hNaCaYnFOFR3t5_gyP8-zAwHTf1rXNm2iqGzcR31TlK4UQQQUYQPKFr0m9mitAvYYve-F6uNvwjllm2YksO4iGpJtDHb4yGEnjPHXjGhWshm-aR9onZRh7M88yNGq_-SzjifTqENUtlGiiGd26OjfPsXMA_cT_-f-LAhn-kCZTBkhbXPw-NvB096XoPh8UbmyEkaFfYgatT08cYujPCm-rnns85eqo8AHIybUQDYcvCmHEcfnRIaRYNhOymm4oRIGbdHMUF-kQn5MzN6u7i4k6c._K6QVwwmErVx4RHONiO5sE-EL1JTqvVPVNHuyDNhuMs&dib_tag=se&keywords=induction%2Bmelting%2Bfurnace&qid=1786996661&sprefix=induction%2Bfurnace%2Caps%2C126&sr=8-25&th=1

No, I don't work in a steel mill, but I like videos of steel mills. What I notice, is that reheating slabs or bars, after being cast in the continuous caster, they are reheated but they use gas furnaces. Why not by induction ? That is much more energy efficient, because heat is only generated inside the steel. And why are the slabs stored and reheated later on (which is a waste of energy), rather than let the continuous caster feed the roughing mills ?

Images of my home stored in the cloud I consider as a security risk, so I want to store the images locally, such as on the device itself or on a NAS.

Do such cameras exist ?

In my prooted Debian sound does work when using a music player started from XFCE, but not in Firefox.

Before launching proot-distro I run pulseaudio --start --exit-idle-time=-1 and set export PULSE_SERVER=tcp:127.0.0.1:4713.
Audio works over TCP. And pactl info returns

myuser@localhost:~$ pactl info
Server String: 127.0.0.1
Library Protocol Version: 35
Server Protocol Version: 35
Is Local: no
Client Index: 9
Tile Size: 65472
User Name: u0_a221
Host Name: localhost
Server Name: pulseaudio
Server Version: 17.0-dirty
Default Sample Specification: s16le 2ch 44100Hz
Default Channel Map: front-left,front-right
Default Sink: OpenSL_ES_sink
Default Source: OpenSL_ES_sink.monitor
Cookie: 0304:c613

But when launching Firefox in the same XFCE session it remains silent.

In theory this is true, but because with decreasing wavelength (red => blue, violet) the light output decreases almost inversely. Blues and violets are poorly rendered with an incandescent.
So actually I don't agree with the '100'.

I found a page https://github.com/coderredlab/proroot/tree/main/ in which the developer claims it has 'zero ptrace overhead'. But it is probably in its alpha stage.
Too good to be true ?
Does it allow usage of GPU from the proot session ?

I tried chroot-distro on my rooted Nothing 2a with Android 14. It did work, even in GUI mode. I used VNC like I use it with proot-distro, because Termux X11 cannot be shared / networked. I use a TigerVNC server (localhost only) inside the proot/chroot with an SSH wrapper for security to access it from LAN. On the phone itself I use a VNC client (AVNC) to control / view it. Works on both proot and chroot.

So far so good.

Chroot is a lot faster, particularly with Firefox or other hardware based graphics because proot has ptrace overhead slowing it down.

BUT:

• root user is shared with Android root which has some security risks. This is unlike a container package like Proxmox/LXC which puts container root to UID 100000 on the Proxmox server.

• the standard non root user (UID 1000) is shared with 'Android system'. This can be avoided by patching /etc/passwd inside the container (when it is not running) from a root shell in Termux. The UID can be patched to the same UID as Termux (10xxx . u0_axxx).

• But when installing other apps inside the container by adb / dnf / (the package manager of the OS), some apps have their own Linux user (e.g. Apache UID 48, or mysql user). That is the other issue they 'steal' the UID from Android when it is used under Android. This is the same difference with LXC where Apache in a container has UID 100048 on the server.

• Mounts should be cleared completely after exiting / stopping or even aborting the container. And use the --minimal option on chroot-distro command to prevent unnecessary and risky mounts to the Android root folder like /tmp, /acct, /data which should not be accessed from the container. Otherwise one could mess up Android.

Doing any actions to the container folder when it is not running should be done only when all mounts to the container are unmounted.

Once I did a su -c "rm -rf $ROOTFS/data" from Termux when it was still mounted to /data which wiped my entire phone. So I had to factory reset it, but luckily root and Magisk survived.

This fundamental issue keeps me from using chroot.

This is a warning that chroot is risky, more than most apps using root.

It was already a few years ago, I have no photos. The closet (an IKEA built in one) in our master bedroom has two sliding doors with (luckily safety-) glass windows in it in an aluminum frame.
Suddenly in a early morning one of them spontaneously shattered, luckily far enough from our beds that glass shards did not reach us.

How is that possible ?

These OS'es are much stricter on security now, which is a good thing, and yet, still some flaws exist. I've read that Android 17 had a new permission for access to LAN. But why no permission to access the internet ? That is a much more security thing. Most malware reaches your device because all apps have unlimited internet access while not needed in some cases.

Moreover there is no setting to block incoming traffic. When e.g. in a public wifi, incoming traffic must actually be blocked. I have a script on my phone (thanks to root) which toggles incoming traffic and I use Netguard or RethinkDNS to block internet access to most apps. Such a possibility should be available to all devices.

When using a public wifi hotspot (and even with VPN ON, not all VPN apps block incoming traffic), other people can access your phone by using wifi ADB or other open ports from apps (some use http 8080).
Firewall VPNs like Netguard or Rething DNS do NOT block this.

I have only one option (rooted devices only) change IPtables: To be run as root:

#!/system/bin/sh

IFACE=wlan0

add_rule() {
    # Only insert if rule doesn't exist yet
    iptables -C "$@" 2>/dev/null || iptables -I "$@"
}

add_rule6() {
    ip6tables -C "$@" 2>/dev/null || ip6tables -I "$@"
}

del_rule() {
    # Only delete if rule exists
    iptables -C "$@" 2>/dev/null && iptables -D "$@"
}

del_rule6() {
    ip6tables -C "$@" 2>/dev/null && ip6tables -D "$@"
}

block_incoming() {
    add_rule  INPUT -i $IFACE -p icmp -j ACCEPT
    add_rule  INPUT -i $IFACE -m state --state ESTABLISHED,RELATED -j ACCEPT
    add_rule  INPUT -i $IFACE -m state --state NEW,INVALID -j DROP

    add_rule6 INPUT -i $IFACE -p icmpv6 --icmpv6-type neighbor-solicitation -j ACCEPT
    add_rule6 INPUT -i $IFACE -p icmpv6 --icmpv6-type neighbor-advertisement -j ACCEPT
    add_rule6 INPUT -i $IFACE -p icmpv6 --icmpv6-type router-advertisement -j ACCEPT
    add_rule6 INPUT -i $IFACE -m state --state ESTABLISHED,RELATED -j ACCEPT
    add_rule6 INPUT -i $IFACE -m state --state NEW,INVALID -j DROP
}

unblock_incoming() {
    del_rule  INPUT -i $IFACE -p icmp -j ACCEPT
    del_rule  INPUT -i $IFACE -m state --state ESTABLISHED,RELATED -j ACCEPT
    del_rule  INPUT -i $IFACE -m state --state NEW,INVALID -j DROP

    del_rule6 INPUT -i $IFACE -p icmpv6 --icmpv6-type neighbor-solicitation -j ACCEPT
    del_rule6 INPUT -i $IFACE -p icmpv6 --icmpv6-type neighbor-advertisement -j ACCEPT
    del_rule6 INPUT -i $IFACE -p icmpv6 --icmpv6-type router-advertisement -j ACCEPT
    del_rule6 INPUT -i $IFACE -m state --state ESTABLISHED,RELATED -j ACCEPT
    del_rule6 INPUT -i $IFACE -m state --state NEW,INVALID -j DROP
}

case "$1" in
    block)   block_incoming ;;
    unblock) unblock_incoming ;;
    *)       echo "Usage: $0 {block|unblock}" ;;
esac

I installed Tasker from tasker.joaoapps.com/download.html, but it lacks an input for the license key. Preumably it is the Play store version.
Where can I get the non-play store version ?

The per app rules in Rethink have no add button to add an app or port or IP.

Moreover there is no option to block incoming connections (e.g. wifi ADB, ssh into Termux, web interface if the phone runs a web server) when in a public wifi hotspot. This is a nasty security leak of Android.

Nothing 2a, Android 14 (stock ROM).

I had this version, but Wireguard did not work. Then I uninstalled it, reinstalled 0.55t from Github and could not use it as a VPN.
I uninstalled again and reinstalled from f-droid, but same issues.
Settings => VPN => RethinkDNS was not listed.

I successfully use proot with Debian Trixie.
Most apps run adequate, even Stellarium or Rawtherapee. Only Firefox is slow. I have a (rooted) Nothing 2a with 12GB RAM.
My question is: can I run chroot-distro on the same proot container ? And whar should I change in that container ?

The 'container' is just a folder with all standard Linux folders.

#!/bin/bash

WIDTH=1440
HEIGHT=800
RATE=60
OUTPUT="VNC-0"

# Generate modeline
LINE=$(gtf $WIDTH $HEIGHT $RATE | grep Modeline)

# Extract mode name (e.g. "1200x600_60.00")
MODENAME=$(echo $LINE | awk -F'"' '{print $2}')
#MODELINE=$(echo "$MODENAME" | sed 's/^Modeline.+$//')
MODELINE=$(echo $MODENAME | sed 's/^\s*Modeline.+$//')
echo 1: $MODENAME
echo 2: $MODELINE
echo 3: $LINE

exit

It appears that the line

MODELINE=$(echo $MODENAME | sed 's/^Modeline.+$//')

refuses to skip the word 'Modeline' (optionally prepended by space) which is the start of the line. What am I doing wrong ?

 Modeline "1440x800\_60.00" 93.80 1440 1512 1664 1888 800 801 804 828 -HSync +Vsync