Thank you NurgulG for your answer
PS : we set VIRTUALIZATION_HOSTS_SECURE_CONNECT_ENABLED to NO
it was resolved by entering "admin@internal" in the username field in place of root (even admin without @internal wouldnt work)
we can now successfully add the RHVM in NetBackup webui and get all its VMs.
but the backup of VM fails after creating the protection plan to backup VMs
here below job details
janv. 24, 2023 1:15:07 PM - Info nbjm (pid=320782) starting backup job (jobid=45) for client a5f7cdb3-818d-4e87-b475-940c5d4ee07a, policy BACKUPNOW+4287d509-a726-467b-bd7a-a55ebc830061, schedule FULL_be31d543-b1e4-4dfe-841a-84d915623a2f
janv. 24, 2023 1:15:07 PM - 0 ko estimés nécessaires
janv. 24, 2023 1:15:07 PM - Info nbjm (pid=320782) started backup (backupid=a5f7cdb3-818d-4e87-b475-940c5d4ee07a_1674562507) job for client a5f7cdb3-818d-4e87-b475-940c5d4ee07a, policy BACKUPNOW+4287d509-a726-467b-bd7a-a55ebc830061, schedule FULL_be31d543-b1e4-4dfe-841a-84d915623a2f on storage unit stu_disk_srv-backup using backup host srv-backup
janv. 24, 2023 1:15:07 PM - Info bpbrm (pid=303096) The data-in-transit encryption (DTE) is disabled for the client (srv-backup) as the global DTE mode is set to 'Preferred Off' and the client DTE mode is set to 'Automatic'
janv. 24, 2023 1:15:07 PM - processus démarré bpbrm (pid=303096)
janv. 24, 2023 1:15:08 PM - Info bpbrm (pid=303096) a5f7cdb3-818d-4e87-b475-940c5d4ee07a is the host to backup data from
janv. 24, 2023 1:15:08 PM - Info bpbrm (pid=303096) reading file list for client
janv. 24, 2023 1:15:08 PM - Info bpbrm (pid=303096) starting bpbkar on client
janv. 24, 2023 1:15:08 PM - Info bpbkar (pid=303106) Backup started
janv. 24, 2023 1:15:08 PM - Info bpbrm (pid=303096) bptm pid: 303125
janv. 24, 2023 1:15:08 PM - Info bptm (pid=303125) start
janv. 24, 2023 1:15:08 PM - Info bptm (pid=303125) using 262144 data buffer size
janv. 24, 2023 1:15:08 PM - Info bptm (pid=303125) using 30 data buffers
janv. 24, 2023 1:15:08 PM - Info bptm (pid=303125) start backup
janv. 24, 2023 1:15:08 PM - connexion
janv. 24, 2023 1:15:08 PM - connecté ; temps de connexion : 0:00:00
janv. 24, 2023 1:15:09 PM - début de l’écriture
janv. 24, 2023 1:15:10 PM - Info bpbkar (pid=303106) INF - Backing up Hypervisor Type RHV, VM Server 192.168.3.28, VM GUID a5f7cdb3-818d-4e87-b475-940c5d4ee07a, Display Name zmstore02
janv. 24, 2023 1:15:11 PM - Warning bpbrm (pid=303096) from client a5f7cdb3-818d-4e87-b475-940c5d4ee07a: WRN - Failed to download the disk. Error: Couldn't resolve host name
janv. 24, 2023 1:15:12 PM - Warning bpbrm (pid=303096) from client a5f7cdb3-818d-4e87-b475-940c5d4ee07a: WRN - Failed to download the disk. Error: Couldn't resolve host name
janv. 24, 2023 1:15:13 PM - Warning bpbrm (pid=303096) from client a5f7cdb3-818d-4e87-b475-940c5d4ee07a: WRN - Failed to download the disk. Error: Couldn't resolve host name
janv. 24, 2023 1:15:14 PM - Warning bpbrm (pid=303096) from client a5f7cdb3-818d-4e87-b475-940c5d4ee07a: WRN - Failed to download the disk. Error: Couldn't resolve host name
janv. 24, 2023 1:15:16 PM - Info bpbkar (pid=303106) 58 entries sent to bpdbm
janv. 24, 2023 1:15:16 PM - Warning bpbrm (pid=303096) from client a5f7cdb3-818d-4e87-b475-940c5d4ee07a: WRN - Failed to download the disk. Error: Couldn't resolve host name
janv. 24, 2023 1:15:16 PM - Warning bpbrm (pid=303096) from client a5f7cdb3-818d-4e87-b475-940c5d4ee07a: WRN - Failed to download the disk. Error: Couldn't resolve host name
janv. 24, 2023 1:15:16 PM - Warning bpbrm (pid=303096) from client a5f7cdb3-818d-4e87-b475-940c5d4ee07a: WRN - Failed to download the disk. Error: Couldn't resolve host name
janv. 24, 2023 1:15:16 PM - Warning bpbrm (pid=303096) from client a5f7cdb3-818d-4e87-b475-940c5d4ee07a: WRN - Failed to download the disk. Error: Couldn't resolve host name
janv. 24, 2023 1:15:16 PM - Warning bpbrm (pid=303096) from client a5f7cdb3-818d-4e87-b475-940c5d4ee07a: WRN - Failed to download the disk. Error: Couldn't resolve host name
janv. 24, 2023 1:15:17 PM - Warning bpbrm (pid=303096) from client a5f7cdb3-818d-4e87-b475-940c5d4ee07a: WRN - Failed to download the disk. Error: Couldn't resolve host name
janv. 24, 2023 1:15:18 PM - Warning bpbrm (pid=303096) from client a5f7cdb3-818d-4e87-b475-940c5d4ee07a: WRN - Failed to download the disk. Error: Couldn't resolve host name
janv. 24, 2023 1:15:19 PM - Warning bpbrm (pid=303096) from client a5f7cdb3-818d-4e87-b475-940c5d4ee07a: WRN - Failed to download the disk. Error: Couldn't resolve host name
janv. 24, 2023 1:15:35 PM - Critical bpbrm (pid=303096) from client a5f7cdb3-818d-4e87-b475-940c5d4ee07a: FTL - cleanup() failed, status 11
janv. 24, 2023 1:15:37 PM - Error bptm (pid=303125) media manager terminated by parent process
janv. 24, 2023 1:15:41 PM - Info srv-backup (pid=303125) StorageServer=PureDisk:srv-backup; Report=PDDO Stats (multi-threaded stream used) for (srv-backup): scanned: 2 KB, CR sent: 0 KB, CR sent over FC: 0 KB, dedup: 100.0%, cache disabled, where dedup space saving:100.0%, compression space saving:0.0%
janv. 24, 2023 1:15:42 PM - Critical bpbrm (pid=303096) unexpected termination of client a5f7cdb3-818d-4e87-b475-940c5d4ee07a
janv. 24, 2023 1:15:42 PM - Info bpbkar (pid=0) done. status: 11: system call failed
janv. 24, 2023 1:15:42 PM - fin de l’écriture ; temps d’écriture : 0:00:33
échec d'appel système(11)