Earth Notes: On Website Technicals (2023-05)

Updated 2023-06-16.
Tech updates: bang, 512GB SD, one OS to run them all.
Mid-month the off-grid Raspberry Pi's power supply failed badly, killing the Pi but thankfully not the SD card or anything else...

2023-05-22: You Have Mail!

The SD cards arrived this afternoon.

Though I cannot devote huge amounts of mental effort to this now, I am using the Raspberry Pi Imager v1.7.4 to put a Raspberry Pi OS Lite (32-bit) (Debian Bullseye port, released 2023-05-03, 0.4GB) on each card. Such an OS should run on any RPi, including 2 and 3 that I have, and the 4 that I have borrowed.

This installation partly serves as a test that the SD cards are not fake!

64GB card write/verify started at ~17:30 and took a couple of minutes.

Setting up as sencha2.local with SSH (no passwords allowed), a user ID, access to WiFi, timezone Etc/UTC.

512GB card write/verify started at ~17:34 and also took a couple of minutes, and is sencha3.local.

This implies that the main (ext4?) filesystem is not finalised yet.

Boot test

18:11 (17:11Z) RPi4 with no SD card, USB keyboard, shows error HDMI screen.

18:16 put 64GB card in RPi4 and powering it up again, and the RPi boots, Generating SSH keys... ... and reboots. I was offered a command-line login prompt for a few tens of seconds, and the system rebooted. This time I have logged in.

Using df -h shows 55GB out of 59GB available in /.

Using poweroff I have shut the RPI4 down, and then unplugged its power.

18:25 the RPi2B boots from the very same SD card, lets me log in, etc! Wow!

2023-05-19: 512GB microSDXC

Given that I was caught short when my RPi3B died, and that I could easily have had a damaged/destroyed SD card too, I'm buying another to be better prepared.

The existing Samsung EVO Plus 256 GB microSDXC UHS-I U3 100 MB/s Full HD & 4K UHD Memory Card with Adapter (MB-MC256GA) - Red/White (C10, U3, A2, V30) cost a small fortune.

A bigger Samsung EVO Select 512GB microSDXC UHS-I U3 130MB/s Full HD & 4K UHD Memory Card inc. SD-Adapter (MB-ME512KA/EU), Blue (apparently the same internals) is just under £40 including VAT, so that is what I will get to allow growing my repos.

I will also get a sub-£8 64GB card (C10, U1, A1, V10) from the same range to allow for experiments and/or an upgrade to the RPi that looks after the Thermino, rather than fight with storage space!

2023-05-16: Bang!

On Friday morning while I was out meeting and greeting Rob Hopkins of Transition Town amongst chickens and toddler, I received a notification that my server was down from the StatusCake monitoring service.

Usually this means that the router has gone down, or the upstream connection.

In this case as it turned out when I had got home, the wired-in 12V to 5V (3A) converter and the Raspberry Pi had both failed. (Subsequently it seems that the converted failed in a bad way, connecting its '5V' outputs directly to the up-to-15V input!)

No Raspberry Pi 3Bs were available from the official distributors, so I had to eat a ~30% markup from a scalper on Amazon, and bought a replacement DC converter too. Now I'm feeling twitchy about that converter, which may accelerate my move to a newer RPi and OS image.

The Amazon order only turned up a little before 8pm Monday evening but I was quickly able to check that the SD card worked in the new RPi3B.

I forced an fsck of the filesystems, which left some footprints in log files from when there was no networking (or NTP) or sensors.

I backed up the SD card to my Mac as a raw dd image, which took some hours, and maybe I could have done earlier in the day. It will be moved off to my archive disk ASAP!

The RPi server was back before midnight (~22:15Z).