Dev Ups

Published 2023-10-01 in hardware

Repurposing the 10ZiG 4478 thin client

I've been following parkytowers.me.uk for a long time. I often check that site when I can't be bothered opening my own thin clients' cases.

I was accessing my 10ZiG's firmware when I realised how few places contain information as essential as the default BIOS password. What if Parky ever stops hosting?

I've already made my own power measurements whilst making a NAS from a thin client. I made no apologies for that, measure twice, as they say. Parky Towers is using a slightly obscure minimal Linux OS for consistency. In Ubuntu, I'm being more prosaic.

Password

The BIOS password defaults to 10ZIG. In all my 10 Zig devices it does. I don't change or clear it. A sticker on the side reminds me of this, and to hit Escape to enter BIOS.

44xx

The exact model is 4472. It sports a cheap, dual-core Atom E3825. Very efficient, very low power.

10Zig 4472 in profile

I have an 8GB stick of ram and mSATA disk sitting idle in it. Underneath the mSATA disk is a mini PCIe socket, where I can add networking. The clearance from the mSATA is potentially an impediment to cool running. Here is the mSATA SSD, obscuring the mPCIe.

Space for RJ45 cutout

For the RJ45 ports, I could cut the metal above the power, or more probably, above a DVI port:

Rear panel of 10Zig 4472

For illustration, here is the plan view of the internals:

Rear panel of 10Zig 4472

Problem

I had a problem that lead me to shelve this unit in 2021. The disk stopped accepting writes, although the OS was functioning just fine. I ran out of ideas to fix it, rebooted, and it never came back up.

A disk becoming read-only is a symptom of impending flash failure. Actually, I think the CMOS battery failed, and defaulted to booting to internal eMMC. That doesn't explain why I could not write to disk. Also, the clock still appears perfectly accurate after months in storage.

I checked my AliExpress order history. I got refunded in Q1 2020 for the disk. Was it a BIOS glitch? A bad block? Is the disk actually bad?

I can fix boot order using grub on a USB stick. And spare parts. Always keep spare parts. With that out of the way, I will continue.

Repurpose

Running on bare metal benefits critical services. The units can be made redundant and fungible for a HA scenario.

I was emailing Parky Towers to contribute in 2021, between contracts. I'll just blog about my own "discoveries" here. Also, his content can be in the nicest possible way, shallow. It is targeted. It is a hub of useful information.

Summary

Default BIOS password is 10ZIG. Pulls 5 Watts as a router, constantly, with very slow USB ethernet (RD9700, circa May 2019) connected.

USB to ethernet

I checked the USB to ethernet bridge device's advert. It's been 4 years since I bought it. I can't tell what has changed since. The pictures clearly proclaim 10Mbps, and Linux support, which, together with the low price, would have swayed me. In 2019 My Internet was only 10Mbps, so I wouldn't have cared. The blurb states:

Networkadapter IC is RD9700 ,it supports maximum Ethernet speed is 100Mbps

I see my Internet "speed test" capped at 5 MBps! I believe it is USB 1.0 and/or Ethernet 10 Mbps. Right now it is doing its job, just slowly. I ordered a bunch more, for spares and stuff.

Meanwhile, I found a USB 3 Gigabit Ethernet adapter on eBay. With it, the router now flies, but does need another half Watt or so.

All the other adapters arrived from China and are way faster than the RD9700. One is incompatible with default freeBSD drivers, however.

Next steps

I installed a network appliance on this. I like the USB adapters, but really, one ethernet port is sufficient with VLANs. That being the case, experimenting on thin clients has inspired me to keep a proxmox server up, with pfsense fully virtualised. On the other hand laptops are now powerful enough to virtualise K8s clusters.

Having the extra USB adaptors makes a second WAN for failover possible. Mobile dongles used to be USB, but I think RJ45 is the most common modem interface currently.

Modern systems engineering is a balance between highly available, redundant services, versus efficiency.