CMK version: 2.5.0p17 Community Edition (Container)
OS version: VyOS Stream 2026.03 (Linux vyos 6.6.128-vyos #1 SMP Mon Mar 16 10:04:04 UTC 2026 x86_64 GNU/Linux, Podman version 4.9.5)
Error message:
I have configured the container to use tmpfs but during start of the container it seems like it actively disables this on its own even if the line before looks OK according to the log?
Log from startup:
Oct 31 18:21:33 vyos checkmk[20650]: ### CREATING SITE 'cmk'
Oct 31 18:21:33 vyos checkmk[20650]: Adding /opt/omd/sites/cmk/tmp to /etc/fstab.
Oct 31 18:21:33 vyos checkmk[20650]: Going to set TMPFS to off.
Oct 31 18:21:48 vyos checkmk[20650]: Executing post-create script "01_create-sample-config.py"...OK
Container config in VyOS:
set container name checkmk allow-host-networks
set container name checkmk environment CMK_PASSWORD value 'CHANGEME'
set container name checkmk environment TZ value 'Europe/Stockholm'
set container name checkmk image 'docker.io/checkmk/check-mk-community:2.5.0p17'
set container name checkmk memory '4096'
set container name checkmk restart 'on-failure'
set container name checkmk tmpfs tmp destination '/opt/omd/sites/cmk/tmp'
set container name checkmk tmpfs tmp size '2048'
set container name checkmk volume monitoring destination '/omd/sites'
set container name checkmk volume monitoring source '/config/container/checkmk'
- How to I properly verify if CheckMK is actually using tmpfs or not (seems like it refuses to)?
When I enter the context of the container using:
sudo podman exec -it <id> /bin/bash
It do seem like its using the tmpfs properly, then why the “Going to set TMPFS to off” message?
root@vyos:/# mount | grep -i tmpfs
tmpfs on /dev type tmpfs (rw,nosuid,size=65536k,mode=755)
tmpfs on /etc/resolv.conf type tmpfs (rw,relatime,size=3288488k,mode=755)
tmpfs on /etc/hosts type tmpfs (rw,relatime,size=3288488k,mode=755)
shm on /dev/shm type tmpfs (rw,nosuid,nodev,noexec,relatime,size=65536k)
tmpfs on /run/.containerenv type tmpfs (rw,relatime,size=3288488k,mode=755)
tmpfs on /etc/hostname type tmpfs (rw,relatime,size=3288488k,mode=755)
tmpfs on /opt/omd/sites/cmk/tmp type tmpfs (rw,nosuid,nodev,relatime,size=2097152k)
tmpfs on /proc/acpi type tmpfs (ro,relatime,size=0k)
udev on /proc/kcore type devtmpfs (ro,relatime,size=16415972k,nr_inodes=4103993,mode=755)
udev on /proc/keys type devtmpfs (ro,relatime,size=16415972k,nr_inodes=4103993,mode=755)
udev on /proc/timer_list type devtmpfs (ro,relatime,size=16415972k,nr_inodes=4103993,mode=755)
tmpfs on /sys/firmware type tmpfs (ro,relatime,size=0k)
tmpfs on /sys/dev/block type tmpfs (ro,relatime,size=0k)