Logbook

Designing rolodex(1)

I'm working on a rolodex command line tool, to help manage a set of Markdown files that each represent some contact information about a person or organization. This is mostly to jog my mind about how I know people.

With the pandemic going on, it's harder than ever to casually meet people in person. I find that my notes often have a brief record of where we met and what we ate. Those opportunities are increasingly scarce, so I'm spending the time preserving memories.

The data structure I'm starting with is a set of Markdown files with names like "Firstname-Lastname.md" in a Git repository. I'd like to preserve that on-disk data structure, rather than represent documents in a database of some kind, for maximum portability among all of the other tools that I'm using.

Markdown files have front matter and free text. At least one of the command line options should be able to read a field or set of fields from the front matter and print it out in a structured format that lets me feed it into something else. There should also be a way to update the front matter in place. The front matter is essentially a key value store.

So far I have a 100+ line shell script that implements the following verbs:

edit address callsign twitter grep spin recent push pull status diff lint help bugs

I'm not trying to be super fancy with any of this, and the script has some rough edges and emergent behavior that isn't yet particuarly well documented. But it is helpful so far.

usb-storage.quirks setting on Raspberry Pi to avoid UAS issues and system lockup

One of my Raspberry Pi 4's was crashing mysteriously every few weeks. I'd get this error message

kex_exchange_identification: Connection closed by remote host when trying to log in. It would respond to pings, though, so something was still up.

That particular Pi is booting from a USB device. I had reason to believe that the device was going into read-only mode when it crashed. This led me to detailed examination of the dmesg logs after a reboot - usually nothing untoward was showing up.

Lately though I have seen something like this in the dmesg log:

uas_eh_abort_handler 0 uas-tag 6 inflight: CMD OUT

If you go down the UAS rabbit hole, you'll find that some devices support it well, and other devices have buggy hardware/firmware/drivers that will trigger errors. This list from the Sunxi wiki is a useful reference. If you don't want to go down the rabbit hole, the relatively straightforward thing to try is to disable the UAS driver using a usb-storage.quirks setting in your blacklists or in cmdline.txt.

The Raspberry Pi Forum post on USB3.0 SSDs will be what you want to look at - it goes into lots of detail for describing how to determine the parameters for the quirks setting. I used lsusb myself. What matters is that you may need to disable UAS and replace it with the older usb-storage driver which is said to be a bit slower but more reliable on some hardware.

The Pi was only locking up every month or so - as a consequence I am not 100% sure yet that this fix is the only change I'll need to make. But it does look like progress!