----------------------------------------------------------------------------------
@MSGID: 3:633/10 88843049
@REPLY: 3:633/10 57905458
@PID: PyGate 1.5.19
@TID: PyGate/Linux 1.5.19
@NOTE: slrn/1.0.3 (Linux)
@CHRS: ASCII 1
@TZUTC: 1100
${send-direct-email-to-news1021-at-jusme-dot-com-if-you-must}@jusme.com
n>
@REPLYTO: 3:633/10 UUCP
send-direct-email-to-news1021-at-jusme-dot-com-i@vm46.home.ju
sme.com>
On 2026-08-04, Chris Green <cl@isbd.net> wrote:
> s|b <me@privacy.invalid> wrote:
>> On Mon, 3 Aug 2026 18:29:55 +0100, The Natural Philosopher wrote:
>>
>> > in the true `if i wanted to go there i wouldn`t be starting from here`
>> > tradition if its a 2W why not send its data to somewhere more
>> > interesting and secure?
>> >
>> > My Pi zero W never writes to its SD car at all unless i change
>> > configurations,. Everything that writes is either stopped from writing
>> > or writes to ram discs.
>> >
>> > Some SD cards are better than others, I am not interested in finding out
>> > which
>>
>> This is helpful.
>>
> What would be more helpful would be some guidance on how to implement
> it! :-)
>
> E.g. how do you stop systemd`s logging from writing to `hard` disk?
> It would need a **lot** of reconfiguration before it would use a
> reasonable amount of space such as is available on a RAM drive.
>
> Maybe there are versions of the OS that are optimised for minimal disk
> writing, if so I`d like to know about them.
Wot I do:
Replace /sbin/init with a shell script that sets up the minimal necessary
for the application. That script runs with the root filesystem mounted
read-only, so the SD card is never written to in noral operation. To
modify the config:
mount -o remount,rw /dev/root /
It also means you can safely "pull the plug" at any time without risk of
corruption (useful for PoE devices).
Here`s an example for debian 9.4 (stretch):
-----------------------------------------------------------------------
#!/bin/bash
clear
echo "Running ${0}..."
#
# Config...
#
source /etc/ro-config
export OUR_BC="${OUR_IP%.*}.255"
export OUR_GW="${OUR_IP%.*}.1"
#
# Need to set these so we can prime PS1 for bash...
# (see nonsense in /etc/bash.bashrc)...
#
export SUDO_USER=0
export SUDO_PS1="-"
#
# Mount tmpfs filesystems on /run and /tmp,
# as these need to be rw...
#
mount -t tmpfs -o size=256m tmpfs /run
mount -t tmpfs -o size=10m tmpfs /tmp
mkdir /run/lock
mkdir /run/log
#
# Need /dev/pts for ssh...
#
mkdir /dev/pts
mount -t devpts devpts /dev/pts
#
# Need loopback...
#
ifconfig lo up
#
# Need /proc...
#
mount -t proc none /proc
#
# Pop a shell here while we set up the network...
#
#PS1="TEMP-SHELL% " /bin/bash
#
# Set host name and domain name...
#
hostname "${OUR_HOSTNAME}"
domainname "${OUR_HOSTNAME#*.}"
#
# If wifi, set up the wireless interface...
#
[ "${WIRED}" != "1" ] && /ro/init-wifi
#
# Wait for interface to appear before
# configuring it...
#
while [ ! -d "/proc/sys/net/ipv4/conf/${OUR_IF}/" ]
do
echo "Waiting for interface "${OUR_IF}"..."
sleep 1
done
#
# Bring the interface up...
#
ip link set "${OUR_IF}" up
#
# Check if the MAC address matches the config. If not, don`t
# bring up the network, just pop up a shell to allow the config
# to be updated (allows cloning of the image)...
#
real_eth="$(ip addr list ${OUR_IF} | awk `/link/ether/ {print $2}`)"
if [ "${real_eth^^}" != "${OUR_ETH^^}" ]
then
echo "This MAC address (${real_eth^^}) doesn`t match config (${OUR_ETH^^})"
echo ""
echo "Please edit config and reboot..."
echo ""
cd /ro
./rw
PS1="RW-SHELL \\h:\\w# " /bin/bash
reboot -f
fi
#
# Set the IP address and default route...
#
echo "Setting IP address for ${OUR_IF}: ${OUR_IP}/24, gw: ${OUR_GW}"
ip addr add "${OUR_IP}/24" brd "${OUR_BC}" dev "${OUR_IF}"
ip route add 0/0 via "${OUR_GW}"
#
# Wait for network, check by pinging our default gateway...
#
while ! ping -c 1 -q -w 1 "${OUR_GW}" > /dev/null 2>&1
do
echo "Waiting for network, ping gw (${OUR_GW})..."
sleep 1
done
#
# Pop up a shell here before we start the applications
# while debugging...
#
#PS1="TEMP-SHELL% " /bin/bash
#
# Start ntpd to get the time...
#
echo "Starting ntpd..."
/usr/sbin/ntpd -g
echo "Waiting for time sync..."
ntp-wait -n 30 -s 1
date
#
# Start sshd
#
echo "Starting sshd..."
mkdir /run/sshd
/usr/sbin/sshd
#
# Now start application screen sessions...
#
echo "Starting applications..."
cd /ro
./start-screens
#
# Shell for testing...
#
while true
do
PS1="RO-SHELL \\h:\\w# " /bin/bash
done
#
# We can`t exit from init (causes kernel panic), so force a reboot
if we get here...
#
reboot -f
-----------------------------------------------------------------------
Wifi requires some kernel modules, this is init-wifi:
-----------------------------------------------------------------------
#!/bin/bash
#
# Start wifi...
#
echo "Loading modules for WiFi..."
kernel="$(uname -r)"
for module in net/rfkill/rfkill.ko
net/wireless/cfg80211.ko
drivers/net/wireless/broadcom/brcm80211/brcmutil/brcmutil.ko
drivers/net/wireless/broadcom/brcm80211/brcmfmac/brcmfmac.ko
drivers/input/touchscreen/rpi-ft5406.ko
drivers/input/evdev.ko
do
insmod /lib/modules/${kernel}/kernel/${module}
done
echo "Starting wpa_supplicant..."
find /usr > /dev/null # Generate some entropy
/sbin/wpa_supplicant -B -dd -c/etc/wpa_supplicant/wpa_supplicant.conf -iwlan0
-----------------------------------------------------------------------
--
Ian
"Tamahome!!!" - "Miaka!!!"
--- PyGate Linux v1.5.19
* Origin: Dragon`s Lair, PyGate NNTP<>Fido Gate (3:633/10)
SEEN-BY: 19/10 50/109 153/757 218/840 840 220/70
221/1 6 360 226/17 100
SEEN-BY: 229/426 240/1120 267/800 301/1 113 812
310/31 335/364 341/66 463/68
SEEN-BY: 550/278 633/10 20 280 281 416 418 420
422 509 2744 712/848 770/1 3
SEEN-BY: 770/100 340 772/210 220 230 5001/100
5019/40 5020/715 848 1042 1146
SEEN-BY: 5020/4441 12000 5023/24 5030/49 722 1081
1474 5051/44 5075/128
@PATH: 633/10 280 770/1 218/840 221/6 301/1
5020/1042 4441 715