Where you backing up heavy workloads? Can you give more information about the scenario? 

Hi @Shaokat do you mean when they run the backup EVERYTHING stops? or just becomes slow/unresponsive? Are we talking the production environment or Veeam environment?

Just so we’ve got the basics right.

Hi @MicoolPaul everything not responding stage 

Hello @Shaokat What do you mean by the “network is down”? Could you please reword your question. If everything becomes unresponsive, then it could be that the device utilisation is very high. Please check this.

I think there’s a problem on resource on source host selected for backup. DNS server maybe goes freeze and file server too… Check healthy of that structure in primis (I take for granted that it’s not first try of backup of that structure)

Not sure Veeam One will be the product for your problem. Does your client have a basic monitoring like nagios/centreon/zabbix?

It’s easy to deduce the network bottleneck when you monitor network interfaces or packet dropped of your network equipments… The flow path could be miserable like router or fw who is satured.

Hello, have you managed to resolve this?

Am I the only one not understanding “everything not responding stage“? Why do you think VeeamONE could help you when everything is not responding?

I agree with you! I thing he didn’t articulate the sentence correctly. I also hope our suggestions were able to help him. 

In my opinion it’s clear, there aren’t enough resources/structure has hardware failure, and as soon as backup starts everything sits down (hope this verb isn’t used only in Italy  )
But I agree with you @vNote42 and @chris_eromosele I don’t see how Veeam One can bring something useful...

There is another possibility.

If the vsphere environment is using NFS v3 for accessing the datastore, and hotadd backup mode is used, then stuns on the vms are expected when doing backups.

https://kb.vmware.com/s/article/2010953

This could led applications to stop to working, because database is not reachable.

But without any detailed information about the environment from @Shaokat, it‘s really impossible to give a correct answer.

You are right, @Mildur ! There is already information about this here:

But this is a thing of about under a minute.

Yeah, you are right. Normally it should be finished within a minute.

In rare cases, I have seen stuns longer than a minute, mostly when there was a really great workload on the vm while the backup was running on a rather slow production datastore.

And this during a vCenter-Backup could lead to the impression that everything is offline ...