Hi: I always use network-scripts to start network at EL7. NetworkManager is not as good as network scripts under that OS.
but now EL8 said that network-scripts is depreciated. I wonder if I should still use network-scripts to start network? I am afraid there will be new bugs for the network-scripts, like systemd service unit dependency. although it is solid at EL7.
Le 29/06/2020 à 10:34, d tbsky a écrit :
Hi: I always use network-scripts to start network at EL7. NetworkManager is not as good as network scripts under that OS.
but now EL8 said that network-scripts is depreciated. I wonder ifI should still use network-scripts to start network? I am afraid there will be new bugs for the network-scripts, like systemd service unit dependency. although it is solid at EL7.
I've written a blog article (in French) about that question :
https://blog.microlinux.fr/networkmanager-rhel-centos/
Cheers,
Niki
On 6/29/20 1:34 AM, d tbsky wrote:
what's the advantage of NetworkManager for server?
The shortest clear answer I can give you is:
In the event of a power loss, many servers will boot faster than the managed Ethernet switch they are attached to. Systems managed by network-scripts may not set up their network because there is no carrier at the time that networks-scripts start up.
Network-manager, on the other hand, will set up networking whenever the interface becomes ready.
On 6/29/20 11:20 AM, Gordon Messmer wrote:
... In the event of a power loss, many servers will boot faster than the managed Ethernet switch they are attached to. Systems managed by network-scripts may not set up their network because there is no carrier at the time that networks-scripts start up.
Network-manager, on the other hand, will set up networking whenever the interface becomes ready.
At $dayjob we got to see the advantages of this up close and personal a few days ago when we had a hard failure in the voltage regulator/exciter loop of one of our three primary generators during a utility power failure. First failure of this kind since that datacenter was placed online in 2008, and only the second power out event since 2008. (While critical systems have dual generator backup, and all systems have UPS with a few minutes run time, the systems affected by this weren't previously classed as 'critical' enough to have dual feeds, although that might change in the next few weeks). So, we have a virtualization host in an IBM Bladecenter with iSCSI shared storage on some EMC Clariion LUNs through a Cisco 7609 switch/router with RSP720. Anyone who has ever dealt with these items in a cold boot situation probably knows how the litany goes at this point.....
Prior to the NetworkManager intelligence, I would have to manually reset the host in the Bladecenter after the EMC was up and after the 7609 was up. Not any more. Nice. (Clariion can take 15-20 minutes to come all the way back up on a hard power fail; 7609 can take 10 minutes if not longer. Bladecenter takes 5 at most.)
Lamar Owen lowen@pari.edu
On 6/29/20 11:20 AM, Gordon Messmer wrote:
... In the event of a power loss, many servers will boot faster than the managed Ethernet switch they are attached to. Systems managed by network-scripts may not set up their network because there is no carrier at the time that networks-scripts start up.
Network-manager, on the other hand, will set up networking whenever the interface becomes ready.
Prior to the NetworkManager intelligence, I would have to manually reset the host in the Bladecenter after the EMC was up and after the 7609 was up. Not any more. Nice. (Clariion can take 15-20 minutes to come all the way back up on a hard power fail; 7609 can take 10 minutes if not longer. Bladecenter takes 5 at most.)
our switches also take long time to be up. and our servers are booting fast. I don't know what's the problem with the situation. with network-scripts, the network settings is ready early. when physical network goes up, the related service is up too. maybe your situation need dynamic logic like dhcp or some kind of timeout so can not wait for long time?
our servers may have team,bridge,vlan and complex routing. with static configuration they work fine. I don't want them up/down with network cable. I want them always setup and ready. I don't know if NetworkManager can handle these correctly with dynamic logic now. in early EL7 days, I have a teamd dependency problem. with network-scrips it can be fixed immediately . but with NetworkManager it is hard to fix. I am afraid these kind of bugs. https://bugzilla.redhat.com/show_bug.cgi?id=1264175
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d tbsky -
Gordon Messmer -
Lamar Owen -
Nicolas Kovacs