Logging stops and files are read only

Setup, Configuration and Use Runtime
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1

Platform information:

  • RPi 3B compute module with openhabian and openHAB 3.2.0
  • 1 Gb RAM
  • 16 Gb SD card class 10

After some hours running the logging stops and the log (:9001) show only the log names

==> /var/log/openhab/openhab.log <==
==> /var/log/openhab/events.log <==

When I check the logs they are read only.

Outputs from free -m:

[09:32:22] openhabian@<hostname>:~$ free -m
              total        used        free      shared  buff/cache   available
Mem:            972         567          53           1         351         387
Swap:          2647          17        2630

and also from FireMotD:

## CPU Usage = 32.65% avg over 4 cpu(s) (4 core(s) x 1 socket(s))
##  CPU Load = 1m: 5.29, 5m: 1.72, 15m: 0.61
##    Memory = Free: 0.04GB (4%), Used: 0.90GB (96%), Total: 0.94GB
##      Swap = Free: 2.58GB (100%), Used: 0.00GB (0%), Total: 2.58GB
##      Root = Free: 6.54GB (48%), Used: 6.82GB (52%), Total: 13.97GB

I have read that it is not recommended to use Zram with SBCs with less than 1 Gb. As the memory log show 972 Mbyte it is slightly less and I wonder if this is significant.

Here is one of the last lines from syslog

Jan 10 06:50:12 <hostname>rsyslogd[820]: file '/var/log/syslog'[7] write error - see https://www.rsyslog.com/solving-rsyslog-write-errors/ for help OS error: Read-only file system [v8.2102.0 try https://www.rsyslog.com/e/2027 ]

Except for the logging, the system seems to work.

What may I do to get logging working as it should? Any help is appreciated

Best regards

Per

2

I am not sure it applies to your situation as you use zram, but readonly files on an SD card often mean that the SD card is broken.

On a failed SD card all the files remain available for reading. You can backup them, but you cannot write anything to the card.

3

It seems that the SD card is in order.
I have tried to reduce log sizes and to increase the /var/log portion of zram to 750 from 600 Mb. But probably not enough to have it stable over a longer period.