how to purchase VMware backup log?

Are you asking what logs to look at for a vm ware backup ?

 

IF so :

1) Modify the following registry on the proxy server with a value of '3' to gather additional API information in the NetBackup logs:
HKEY_LOCAL_MACHINE\SOFTWARE\VERITAS\NETBACKUP\CURRENTVERSION\CONFIG\BACKUP\
Value: vmcloglevel
Value type: DWORD

2) Ensure the following log folders exist:
VMWare Backup Host logs:
<install path>\Veritas\NetBackup\logs\bpfis
<install path>\Veritas\NetBackup\logs\bpcd
<install path>\Veritas\NetBackup\logs\bpbkar
<install path>\Veritas\NetBackup\logs\bpVMutil
C:\Program Files\Common Files\Veritas\VxMS\logs

Media Server side logs:
<install path>\Veritas\NetBackup\logs\bpbrm

3) Replicate the issue

4) Gather the extended logs from the folders in step 2, the job log (detailed status) and the job ID.

5) Please obtain the following ESX Server side log:
/var/log/vmware/hostd.log