LVM2 Fixes for Arch Linux

Alright, so I run Xen on Arch Linux, and I use LVM to manage virtual disks, because snapshots take the pain out of life. There's been a longstanding problem in the hand off from initrd to systemd where not every logical volume is activated at boot, and lvmetad1) will end up running twice with both hanging– in an aggravating but also amusing lock race– when there's a large number of logical volumes.

There was a bug on it, but the bug report suggested that fixes had been implemented and I felt like I was on my own. From there I decided that I wouldn't include root in the LVM, and older systems would just have need intervention on boot. Which is fine– the two affected systems are on my desk or in a datacenter, so inadvertent reboots are rare.

Well, today I decided to patch for Intel-horror, and I really looked at the bug report to fix it once and for all.

It turned out to be absurdly simple.

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2018/01/13 02:54 · sam

Digigram VX222e Isn't Seen in Arch Linux

The card doesn't appear because there is a hardware revision that isn't supported in the current Linux firmware. New drivers are pending.

A radio station I'm working on has a machine with a Digigram VX222e connected to it.

According to the Digigram site, and ALSA, the sound card is supported by ALSA. Unfortunately, it doesn't appear to be detected as a sound card. Reading online, it requires some firmware, but it appears that my system has the proper firmware installed.

The VX222e is a PCIe card, but it appears to be PCI on the card with a PCIe to PCI bridge. According to Digigram's support site, they made a hardware change in March of 2017, and I suspect that this might be the problem.

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2017/08/16 15:18 · sam

Linux, Serial, C, and Intel vs. ARM

I'm working on some mcu stuff and I kept running into the same problems when writing code to talk to it on Linux. I've been writing code on my desktop, moving it to either my Chromebook or an RPi.

So I'm writing it down sos I remember. I thought it might be because of the ch341 UART adaptor I had on my shitty arduino clone, but I'm running into it elsewhere.

  • In c_iflag, IRCNL is set on be default on ARM, converting CR's into NL's. Annoying when you write stuff designed to be understood by humans and machines.
  • cfsetispeed and cfsetospeed don't seem to work. cfsetspeed does.
  • O_NONBLOCK never seems to work right. Leave it alone and use c_cc[VMIN || VTIME] instead, because that's smarter anyway.

There will probably be more here.

2017/06/28 16:51 · sam

Get Out Of Infinality Part 1

This is what I do to my systems to get them up to date with freetype 2.7, which invalidates2) the infinality patches. This assumes you have multilib installed. Remove references to lib32- packages if you don't.

Step 0: Update system and get rid of orphans to make sure things are clean. Make sure you have an alternative wm like windowmaker installed so freetype2 problems aren't deadly.

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2017/01/18 17:08 · sam

vis.nu Cleanup

One of the problems with offering services to friends and acquaintences for free is that when they don't use your stuff anymore, they neglect to tell you.

There's about 18 years of disused email accounts, websites, and all sorts of weirdness in the vis.nu servers, and starting today I'm cleaning it all up. I'm trying to make sure that I'm not getting rid of things that people are using, but rather than erring on the side of caution, I'm erring on the side of personal simplicity.

I'll be saving things for a while, but not likely permanently. If I step on something you want, contact me via mail or FB or whatever and I'll send you a copy. If you want it to stay on my servers, we can discuss that.

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2016/06/17 16:21 · sam

Older entries >>

1)
needed for snapshots
2)
and incorporates some of