The Advisory Boar

By Abhijit Menon-Sen <>

Exactly how much physical memory is installed?

I've often wanted to calculate the exact amount of physical memory installed in a system running Linux, and I finally stumbled across a satisfying solution today: look under /sys/devices/system/memory.

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Nextcloud+OnlyOffice: a self-hosted Google Docs alternative

Running Nextcloud 20 and OnlyOffice 6 is a workable alternative to using Google Docs for collaboration in small, private teams.

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“Possible missing firmware…” warnings from update-initramfs

You're installing a new Linux kernel or drivers or some other package that needs to update your initramfs, and you see a message like this:

update-initramfs: Generating /boot/initrd.img-5.4.0-53-generic
W: Possible missing firmware /lib/firmware/rtl_nic/rtl8125a-3.fw for module r8169
W: Possible missing firmware /lib/firmware/rtl_nic/rtl8168fp-3.fw for module r8169

What does this mean?

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What is fsck up to now?

We had unexpectedly heavy snowfall the other day and, as always, the mains power supply came back only after a few days of repairing broken power lines in the forest. Meanwhile, the days were so overcast that the solar inverter couldn't charge the batteries enough to keep up with our minimal domestic load.

Which meant that when the sun came out again, I was left staring at something like this for a long time:

root@soot:~# ps -eo pid,cmd|grep '[f]sck'
756 /lib/systemd/systemd-fsck /dev/mapper/sdb1_crypt
757 /sbin/fsck -a -T -l -M -C4 /dev/mapper/sdb1_crypt
758 /lib/systemd/systemd-fsckd
759 fsck.ext4 -a -C4 /dev/mapper/sdb1_crypt

Long enough, in fact, that I began to wonder if I could tell what it was doing. (The volume in question is exported via iSCSI from a Synology NAS and fsck is still running long after the machine has otherwise finished booting up, so I have ordinary shell access.)

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I like volumeicon

volumeicon is a small mixer with sensible default behaviour.

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Resolving a conflict between manpages-dev and libbsd-dev

A simple backport from Debian unstable fixed a package conflict that left me without manpages.

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Relaying from Postfix to gmail

Here's how I configured Postfix to relay mail from through using the credentials set up for on Google Apps.

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Raspberry Pi murder

Wherein I try to make a Raspberry Pi rewrite its own SD card image, without success.

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Reading about wireguard

The new Wireguard VPN looks very promising.

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Debian 8 on the Intel NUC5PPYH

Hassath's birthday present this year was an Intel NUC5PPYH (with 8GB of DDR3 RAM and a 250GB SSD) to stand in at home for her ageing Thinkpad X131E. It works fine with Debian 8.

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