Werk #18890: omd: Permission denied: '/omd/sites/xxx/var/omd/tmpfs-dump.tar'

Component

Site management

Title

omd: Permission denied: '/omd/sites/xxx/var/omd/tmpfs-dump.tar'

Date

Jan 26, 2026

Level

Prominent Change

Class

Bug Fix

Compatibility

Compatible - no manual interaction needed

Checkmk versions & editions

2.6.0b1 Not yet released	Checkmk Community, Checkmk Pro, Checkmk Ultimate, Checkmk Ultimate MT
2.5.0b3 Not yet released	Checkmk Community, Checkmk Pro, Checkmk Ultimate, Checkmk Ultimate MT
2.4.0p25 Not yet released	Checkmk Community, Checkmk Pro, Checkmk Ultimate, Checkmk Ultimate MT

If the command omd umount was invoked as a root user, and the file /omd/sites/<site>/var/omd/tmpfs-dump.tar did not exist, then the corresponding file would be created with root permission. The impact of this issue increased due to the cluster failover in Checkmk Appliance often triggering these conditions.

Once this file exists, it can cause the monitoring to stop, or for instance crashes such as this one:

OMD[xxx]:~$ omd umount
...
    fileobj = bltn_open(name, self._mode)
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^
PermissionError: [Errno 13] Permission denied: '/omd/sites/xxx/var/omd/tmpfs-dump.tar'

As of this Werk, omd will always create the file with the correct permissions.

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