CheckMK does not start after change installation disk

bphect1 · March 5, 2025, 8:37am

CMK version:
Open Monitoring Distribution Version 2.2.0p3 cre

OS version:
Red Hat Enterprise Linux release 8.9

Error message:
Fail start with omb start mysite

Temporary filesystem already mounted
Starting agent-receiver...OK
Starting mkeventd (builtin: snmptrap)...Cannot bind UDP socket for snmptrap to port (Is SUID bit set on mkeventd_open514? Is "nosuid" not set on the filesystem?): Permission denied
OK
Starting rrdcached...OK
Starting npcd...OK
Starting nagios...OK
Starting apache...[Tue Mar 04 07:19:06.002249 2025] [auth_mellon:notice] [pid 3129400] MellonDiagnosticsFile has no effect because Mellon was not compiled with diagnostics enabled, use ./configure --enable-diagnostics at build time to turn this feature on.
[Tue Mar 04 07:19:06.002318 2025] [auth_mellon:notice] [pid 3129400] MellonDiagnosticsEnable has no effect because Mellon was not compiled with diagnostics enabled, use ./configure --enable-diagnostics at build time to turn this feature on.
OK
Starting redis...OK
Initializing Crontab...OK

First steps for Troubleshooting

The CheckMK installation is located in /opt/omd within the root partition of the VM:

$ df -h
Filesystem                 Size  Used Avail Use% Mounted on
devtmpfs                   3.8G     0  3.8G   0% /dev
tmpfs                      3.8G     0  3.8G   0% /dev/shm
tmpfs                      3.8G  377M  3.4G  10% /run
tmpfs                      3.8G     0  3.8G   0% /sys/fs/cgroup
/dev/mapper/rootvg-rootlv   33G   12G   21G  37% /
/dev/mapper/rootvg-usrlv    10G  2.4G  7.6G  25% /usr
/dev/mapper/rootvg-varlv   8.0G  3.2G  4.9G  39% /var
/dev/mapper/rootvg-tmplv   2.0G   71M  2.0G   4% /tmp
/dev/mapper/rootvg-homelv 1014M  150M  865M  15% /home
/dev/sdb1                   16G   32K   15G   1% /mnt
tmpfs                      3.8G  5.6M  3.8G   1% /opt/omd/sites/mysite/tmp
/dev/sdc1                   42M  1.5K   42M   1% /mnt/azure_bek_disk
tmpfs                      769M     0  769M   0% /run/user/1001
tmpfs                      3.8G  5.1M  3.8G   1% /opt/omd/sites/sauron/tmp
/dev/sda1                  496M  213M  283M  43% /boot
/dev/sda15                 495M  5.8M  489M   2% /boot/efi

It is desired to move to another disk that has the xfs partition. The procedure followed is as follows:

Stop CheckMK:

omd stop mysite

Mount new disk to directory and copy data:

mount /dev/sdd1 /datos

cp -pr /opt/omd/* /datos

Unmount new disk:

umount /datos

Mount disk in /opt/omd directory

$ cat /etc/fstab
#
# /etc/fstab
# Created by anaconda on Mon Nov 20 06:07:57 2023
#
# Accessible filesystems, by reference, are maintained under '/dev/disk/'.
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info.
#
# After editing this file, run 'systemctl daemon-reload' to update systemd
# units generated from this file.
#
/dev/mapper/rootvg-rootlv /                      xfs     defaults                    0 0
UUID=XXXXXXXX-XXXX-XXXXX-XXXX-XXXXXXXXXXXX /boot         xfs     defaults            0 0
UUID=XXXX-XXXX          /boot/efi                vfat    defaults,uid=0,gid=0,umask=077,shortname=winnt 0 2
/swapfile none swap sw 0 0
/dev/mapper/rootvg-homelv /home                  xfs     defaults                    0 0
/dev/mapper/rootvg-tmplv /tmp                    xfs     defaults                    0 0
/dev/mapper/rootvg-usrlv /usr                    xfs     defaults                    0 0
/dev/mapper/rootvg-varlv /var                    xfs     defaults                    0 0
 
/dev/sdd1 /opt/omd/                              xfs     defaults                    0 0
 
LABEL=BEK\040VOLUME /mnt/azure_bek_disk          auto    defaults,discard,nofail     0 0
tmpfs  /opt/omd/sites/mysite/tmp tmpfs noauto,user,mode=751,uid=mysite,gid=mysite    0 0
/dev/disk/cloud/azure_resource-part1    /mnt    auto    defaults,nofail,x-systemd.requires=cloud-init.service,_netdev,comment=cloudconfig       0       2
tmpfs  /opt/omd/sites/sauron/tmp tmpfs noauto,user,mode=751,uid=sauron,gid=sauron    0 0

$ mount -a

Start the service with the occurring error:

$ omd start mysite
Temporary filesystem already mounted
Starting agent-receiver...OK
Starting mkeventd (builtin: snmptrap)...Cannot bind UDP socket for snmptrap to port (Is SUID bit set on mkeventd_open514? Is "nosuid" not set on the filesystem?): Permission denied
OK
Starting rrdcached...OK
Starting npcd...OK
Starting nagios...OK
Starting apache...[Tue Mar 04 07:19:06.002249 2025] [auth_mellon:notice] [pid 3129400] MellonDiagnosticsFile has no effect because Mellon was not compiled with diagnostics enabled, use ./configure --enable-diagnostics at build time to turn this feature on.
[Tue Mar 04 07:19:06.002318 2025] [auth_mellon:notice] [pid 3129400] MellonDiagnosticsEnable has no effect because Mellon was not compiled with diagnostics enabled, use ./configure --enable-diagnostics at build time to turn this feature on.
OK
Starting redis...OK
Initializing Crontab...OK

aeckstein · March 5, 2025, 9:36am

Hi Hector,

it seems the binary has lost its capabilities during the copy.

Can you look with the getcap command, if the capabilities are set correctly ?

cd /omd/versions/<your_version>/bin
getcap mkeventd_open514

Should be like this:
mkeventd_open514 cap_net_bind_service=ep

Dirk · March 5, 2025, 9:56am

Sounds reasonable. I’m not sure about the copy command (cp -pr). Maybe try

cp -r --preserve=all …

bphect1 · March 5, 2025, 10:01am

Exactly! When I compare both files, the copied one does not have that capability flag, but the original one does.

I will do one thing: tomorrow morning, I will follow the same steps but only copy the ‘sites’ directory. This way, I avoid copying those binaries and potential issues with them. In the end, my goal is simply to have all my checkMK data on another disk to prevent this one from filling up.

Thanks,

aeckstein · March 5, 2025, 10:20am

Hi,

you could also just update checkmk to a higher patch level, this way all the binaries are installed the correct way and then linked from your site.

mike1098 · March 5, 2025, 3:38pm

Would it not be saver to do a backup of the site, uninstall checkmk package, do the mount, re-install package and then restore the backup?

andreas-doehler · March 5, 2025, 9:06pm

That would be the save way

bphect1 · March 6, 2025, 6:33am

I confirm that the issue is resolved with either of the two options:

Update Checkmk after migrating the data
Migrate only the sites directory

Thank you very much for the help!

system · March 6, 2026, 6:34am

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