On a long-running system, it became necessary to allocate / tmp into a separate section in order to prohibit the execution of files and limit the size in case of overflow.
To do this, we had to reduce part of the disk space from the / home partition and give it to the new partition, compress the volume lvm. Then a new volume with a size of 300 megabytes was created, formatted in btrfs and mounted.
However, during server startup, an error appeared in the / var / log / syslog log:
tmp.mount: Directory /tmp to mount over is not empty, mounting anyway.
To avoid this, you need to boot into single mode (recovery mode) before mounting and delete the contents of the / tmp directory. Only then can the partition be mounted.