Category: Misc

Exactly two months ago, on 23 August I posted about munin not creating html pages and that I had to reinstall libxrender1, because the file libXrender.so.1.3.0 was corrupt, but I have not checked the root cause. Well, I should have gone deeper into it, because it turned out that the flash drive was about to break down. So at the end I had to reinstall the whole system. It was not a big deal, but here is how I did it for future reference:

I did a normal install on an SD Card. Then I took a new flash drive, created a single ext4 partition, and read out the DOS disklabel (it has a DOS disklabel, not a GPT) with fdisk -l. The installation creates two partitions on the SD Card, a boot and a root, so I just copied the content of root over to the flashdrive. One last thing to make the system use the flashdrive as root partition is to update /cmdline.txt on the boot partition:

// DOS Disklabel of the flash drive: 0xabcd1234
// Partition number of the root partion on the flash drive: 01
// this needs to be added to the root= parameter
console=serial0,115200 console=tty1 root=PARTUUID=abcd1234-01 rootfstype=ext4 fsck.repair=yes rootwait

During the installation I chose minimal, I also enabled ssh, set the password, and the IP address is assigned via DHCP, so after these steps, I had the basic working setup. I just needed a few more things to have my monitoring stuff with munin. Luckily the old flash drive was not completely broken, so I could save munin configuration (/etc/munin) my custom scripts and plugins (/usr/local/bin and /usr/local/lib/munin) as well as the RRDtool database files (/var/lib/munin), so I copied them onto the new root filesystem before installing munin.

To get munin up and running, I just needed to install lighttpd and munin, and as I read the heating system data via the ModBus protocol, also a small tool called mbpoll. Furthermore, lighttpd needed two lines in the config:

alias.url += ("/munin-static" => "/etc/munin/static" )
alias.url += ("/munin"        => "/var/cache/munin/www/" )

Also for convenience I also installed vim and mc. That’s it.

Last night munin stopped updating the graphs around 2:30 am. A quick check showed that the rrd files are being updated, meaning the data collection was ok. Also looking at the html and png files one could see that they were not changed since 2:30 am. Actually, this is a lesser problem, as the data was still being collected. Honestly, I hate gaps in the graphs. 😀

I tried to generate the files manually and I got the following response:

# su - munin --shell=/bin/bash -c "/usr/share/munin/munin-graph --debug"
Can't load '/usr/lib/arm-linux-gnueabihf/perl5/5.32/auto/RRDs/RRDs.so' for module RRDs: /lib/arm-linux-gnueabihf/libXrender.so.1: unsupported version 0 of Verneed record at /usr/lib/arm-linux-gnueabihf/perl-base/DynaLoader.pm line 187.
 at /usr/share/perl5/Munin/Master/GraphOld.pm line 46.
Compilation failed in require at /usr/share/perl5/Munin/Master/GraphOld.pm line 46.
BEGIN failed--compilation aborted at /usr/share/perl5/Munin/Master/GraphOld.pm line 46.
Compilation failed in require at /usr/share/munin/munin-graph line 49.
BEGIN failed--compilation aborted at /usr/share/munin/munin-graph line 49.

So I have checked libXrender.so.1, it is a symlink to libXrender.so.1.3.0:

# file /lib/arm-linux-gnueabihf/libXrender.so.1.3.0
/lib/arm-linux-gnueabihf/libXrender.so.1.3.0: ELF 32-bit LSB shared object, ARM, EABI5 version 1 (SYSV), dynamically linked, missing section headers

# dpkg -S libXrender.so.1.3.0
libxrender1:armhf: /usr/lib/arm-linux-gnueabihf/libXrender.so.1.3.0

# apt-get install --reinstall libxrender1
Reading package lists… Done
Building dependency tree… Done
Reading state information… Done
0 upgraded, 0 newly installed, 1 reinstalled, 0 to remove and 26 not upgraded.
Need to get 29.9 kB of archives.
After this operation, 0 B of additional disk space will be used.
Get:1 http://mirror.as43289.net/raspbian/raspbian bullseye/main armhf libxrender1 armhf 1:0.9.10-1 [29.9 kB]
Fetched 29.9 kB in 2s (16.1 kB/s)
(Reading database … 115977 files and directories currently installed.)
Preparing to unpack …/libxrender1_1%3a0.9.10-1_armhf.deb …
Unpacking libxrender1:armhf (1:0.9.10-1) over (1:0.9.10-1) …
Setting up libxrender1:armhf (1:0.9.10-1) …
Processing triggers for libc-bin (2.31-13+rpt2+rpi1+deb11u5) …
Segmentation fault

The message “missing section headers” sounds strange, also the Segmentation fault at the end, so some more investigation might be needed. However, after reinstall the .so looks better:

# file /lib/arm-linux-gnueabihf/libXrender.so.1.3.0
/lib/arm-linux-gnueabihf/libXrender.so.1.3.0: ELF 32-bit LSB shared object, ARM, EABI5 version 1 (SYSV), dynamically linked, BuildID[sha1]=24fb04ae1904cc7b7d4f2407d0e62bdedcf7af46, stripped

Unfortunately I have not saved the old libXrender.so.1.3.0 so I cannot check the difference. I wonder what happened to it. Nevertheless munin works again.