On Sat, 20 Mar 2021 08:13:43 +0000, Markus Robert Kessler wrote:

> On Sat, 20 Mar 2021 00:00:55 +0000 Martin Gregorie wrote:
>
> installation was end of November on a fresh 16 GB card.
>
OK, but is it a noname card or from one of the better brands? I've been
using Sandisk for everything (RPi, camera, glider navigation system and
flight logger) a few years now and have had no card-related problems.

> As recommended in this group, I did not perform reboots every day /
> night, since there are only some bash and python scripts running, which
> consume only few resources and are ending after running properly.
>
> $ who -r
>          run-level 3  Nov 30 09:21
> $
> $
> $ df -h Filesystem      Size  Used Avail Use% Mounted on /dev/root
>  15G  2.4G   12G  18% /
> devtmpfs        184M     0  184M   0% /dev tmpfs           216M     0
> 216M   0% /dev/shm tmpfs           216M   22M  194M  11% /run tmpfs
>      5.0M  4.0K  5.0M   1% /run/lock tmpfs           216M     0  216M
> 0% /sys/fs/cgroup /dev/mmcblk0p1  253M   54M  199M  22% /boot tmpfs
>       44M     0   44M   0% /run/user/0 $
> $
OK - nothing wrong so far

> $ cd /etc/resolvconf/update-libc.d $ ll ls: cannot access
> 'avahi-daemon': Structure needs cleaning total 8.0K drwxr-xr-x 2 root
> root 4.0K Feb 13  2020 ./
> drwxr-xr-x 3 root root 4.0K Feb 13  2020 ../
> -????????? ? ?    ?       ?            ? avahi-daemon $ cat avahi-daemon
> cat: avahi-daemon: Structure needs cleaning $ fstrim -a -v /boot: 197.4
> MiB (206990848 bytes) trimmed on /dev/mmcblk0p1 /: 0 B (0 bytes) trimmed
> on /dev/mmcblk0p2 $ ll ls: cannot access 'avahi-daemon': Structure needs
> cleaning total 8.0K drwxr-xr-x 2 root root 4.0K Feb 13  2020 ./
> drwxr-xr-x 3 root root 4.0K Feb 13  2020 ../
> -????????? ? ?    ?       ?            ? avahi-daemon $
>
I think you'll find that avahi-daemon is only needed if your RPi needs to
talk to some sort of Apple computer: here's  synopsis:

The Avahi mDNS/DNS-SD daemon implements Apple's Zeroconf architecture
(also known as "Rendezvous" or "Bonjour"). The daemon registers local IP
addresses and static services using mDNS/DNS-SD and provides two IPC APIs
for local programs to make use of the mDNS record cache the avahi-daemon
maintains. First there is the so called "simple protocol" which is used
exclusively by avahi-dnsconfd (a daemon which configures unicast DNS
servers using server info published via mDNS) and nss-mdns (a libc NSS
plugin, providing name resolution via mDNS). Finally there is the D-Bus
interface which provides a rich object oriented interface to D-Bus
enabled applications.

So, it seems that if you are using Apple kit you need it, otherwise kill
it. I only connect to my RPi from a Linux system, so I don't understand
or use avahi-daemon.


> Well, indeed, I never used fstrim so far.
> But in this case it seems to do nothing, though.
>
OK

> Data is received via I2C bus, processed and transmitted to a webserver
> outside. These are only some Kilobytes, and there is no sensor data
> stored on disk.
>
OK

That looks like all the obvious stuff covered, then.

If nothing else occurs to you or is suggested, check the SD card with
fsck: "fsck -A -s" would seem appropriate and tell it not to fix any
problems if it finds something and asks if it should repair it: IOW treat
this as just a problem scan and only consider what to do if the complete
fsck scan shows any errors.

If errors are found, try to back up anything useful (code, scripts etc
that aren't already backed up) and then, if you're feeling keen back up
the SD card onto new backup media, i.e. don't overwrite a good backup.

Then:
- try using fsck to fix errors. If that works, great.
- otherwise use gparted to clear the SD card, repartition and reformat it
  and copy the backed up stuff back onto it and see if its now OK.
- if still not fixed, repeat the last step with a new disk unless your
  backup was to a new, freshly partitioned and formatted SD card, in
  which case, use that as the RPi's main card and junk toe original.


--
Martin    | martin at
Gregorie  | gregorie dot org

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