Changing Service Start Order on Reboot

[Muckleroy]

I've done quite a bit of searching and I cannot find the answer to this. Perhaps I am looking at the problem incorrectly.

I recently installed Fedora Core 16 on my server. I was running Fedora Core 6 on it previously. I installed all the necessary software and got it all configured and running, however the new DoveCot was a really PITA

Thankfully the server doesn't restart very often but a recent UPS issue has been causing shutdowns and restarts. The UPS solution is simple (replace the battery) but there are several services that are not starting on their own.

Dovecot being one of them.

It seems that the services are trying to start before other required services are running. Zoneminder fails to start because mysqld isn't running. Dovecot fails because the network isn't running for example.

In researching this I see that /etc/rcd.5/Snnmysqld used to be the way mysqld was started after a system restart. It's not there now. The old way (if I understand this correctly) I could just change the nn to a higher number and it would start sooner. I could change zoneminder, for example, to a lower number and it would start later. Actually zoneminder is in this directory as S99zoneminder

So I can probably write something that starts these services after the system is up to resolve this issue, but I'd like to fix it right, again if I am understanding the problem correctly.

[jpollard]

One problem you may get hitting is that unless you take special care, the network is not guaranteed to be available when a service starts.

F16 uses systemd, and it starts everything in a thundering herd manner limited only by some restrictions on dependencies. Unfortunately, it gets some of them wrong.

If you are using NetworkManager to start your networks (the default), then systemd only waits for NetworkManager to start... Not for the network to be ready. to do that you have to "sysctl enable NetworkManager-wait-online.service". Usually, this is sufficient.

To wait for mysqld requires there to be a requirement that it be completed before your service starts. Now because mysqld requires a network, the previous fix MAY cover this as well, but I'm not sure.

Forgot: Try putting the service startup in /etc/rc3.d. I believe this waits for the network to be ready (and should fix the mysqld problem too). I believe it tries to wait for the network, though without the "... wait-online.service" it doesn't necessarily wait.

One last thing. I gave up on NetworkManager - it seems to work acceptably for a single network interface or wireless. I've had problems with it for VMs and multiple wired networks and disabled it entirely, then enabled network - which starts things normally, and you can schedule things appropriately in rc3.d.

[Muckleroy]

Originally Posted by jpollard

One problem you may get hitting is that unless you take special care, the network is not guaranteed to be available when a service starts.

F16 uses systemd, and it starts everything in a thundering herd manner limited only by some restrictions on dependencies. Unfortunately, it gets some of them wrong.

If you are using NetworkManager to start your networks (the default), then systemd only waits for NetworkManager to start... Not for the network to be ready. to do that you have to "sysctl enable NetworkManager-wait-online.service". Usually, this is sufficient.

To wait for mysqld requires there to be a requirement that it be completed before your service starts. Now because mysqld requires a network, the previous fix MAY cover this as well, but I'm not sure.

Forgot: Try putting the service startup in /etc/rc3.d. I believe this waits for the network to be ready (and should fix the mysqld problem too). I believe it tries to wait for the network, though without the "... wait-online.service" it doesn't necessarily wait.

Thanks!

NetworkManager-wait-online.service loaded inactive dead Network Manager Wait Online

The plot thickens...

[marko]

Originally Posted by jpollard

Not for the network to be ready. to do that you have to
"sysctl enable NetworkManager-wait-online.service". Usually, this is sufficient.

If someone has a problem with using that, the command should be spelled systemctl and not sysctl

[jpollard]

Coulda sworn I put the "tem" when I typed...