Cluster Unavailable

[ramihajjiri]

Dear Team,

Recently Veeam is failing my backups of my Hyper-V VMs, then I realized it's not seeing my cluster anymore for some reason.

When I go to the Inventory tab and expand my cluster:


appears an error:


And when I right-click on the cluster and rescan it:


What was recently done before the problem appears?
I just turned off both Hyper-V servers for hardware maintenance purposes.

I have a yearly support contract with Veeam, so please if this is not the right place to post the issue, please tell me where should i post it.


Thanks

[PetrM]

Hello and Welcome to Veeam R&D Forums!

Please provide a support case ID as requested when you create a new topic about a technical issue. As explained there, we cannot troubleshoot technical issues effectively over the forum posts. All posts about technical issues without case ID will be eventually deleted by the forum moderator. You can also upload debug logs for our support as per the instruction of this KB.

Thanks!

[ramihajjiri]

Hello PetrM

It's my first time in here, please tell me how to get a support case ID? it sounds like I have to open a ticket somewhere else.

[PetrM]

Hi Rami,

You may submit a ticket here or contact the support team by phone (look under "Technical Support Phones") and ask our engineers to create a support case.

Thanks!

[s.lienhard@it-sli.de]

Same Problem here
since updating Server 2019 to 10-2022 Veaam can no longer connect to the cluster/hosts.
Deinstalling 8-2022, 9-2022 and 10-2022 helps an Veeam can connect again.
I cannot tell which update exactly is causing this issue, because i deinstalled all three updates at once and restartet Hosts.
2 of 4 Hosts are runnung 9-2022 and Veeam cannot connect, so 10-2022 is likely not the troublemaker.
Case Number is 05675321

best regards
Sebastian

[s.lienhard@it-sli.de]

found this in windows system eventlog
The server-side authentication level policy does not allow the user XXXXX\Administrator SID (S-1-5-21-x-xxxxxxxxxxxxxx-xxxxxxxxxxxx-500) from address 1xx.xx.x.4 to activate DCOM server. Please raise the activation authentication level at least to RPC_C_AUTHN_LEVEL_PKT_INTEGRITY in client application.

[s.lienhard@it-sli.de]

The issue itself is described in more detail here:
https://support.microsoft.com/en-us/top ... ed901c769c

There are two options to resolve this:

1. (Preferred) Install the latest Windows updates on all Hyper-V hosts, the Veeam server, proxies, repositories (or gateway servers), and other servers involved in the backup process.

2. Or add the following key on all Hyper-V hosts, the Veeam server, proxies, repositories (or gateway servers), and other servers involved in the backup process. This key disables the hardening changes for CVE-2021-26414.

Path : HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Ole\AppCompat
Value Name: "RequireIntegrityActivationAuthenticationLevel"
Type: dword
Value Data: 0x00000000

Once one of the above is done, please open the Backup Infrastructure view > Managed Servers > right-click the Hyper-V cluster in question > Properties and go through all the tabs by clicking Next. You shouldn't receive any errors/warnings anymore, and if so, you might retry the backup jobs.

[jorgedlcruz]

Thank you for coming back with a step by step resolution.

I would always recommend first one of course, get components up to sate is vital on pretty much any platform.

But for those with strict policies, thanks a lot for the regedit.

Love the forums when we share knowledge and resolutions.

Thanks

[ramihajjiri]

Thanks for replying,

I have opened a technical ticket with Veeam and they provided the same solution, which is adding the below registry key on hyper-v hosts and restarting them.

Path: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Ole\AppCompat
Value Name: "RequireIntegrityActivationAuthenticationLevel"
Type: dword
Value Data: 0

[spgsit5upport]

That can be as simple issue as Veeam server not being able to resolve IP address of the cluster
Which was what I saw due to the idiotic error: Windows Cluster DNS Error Event ID 1260 - DNS bad key