Preventing browsing delays caused by DNS problems
This topic applies to NetBackup for VMware.
NetBackup may be unable to identify virtual machines when you use the Browse for Virtual Machines dialog. Virtual machine host names may not be properly configured in your Domain Name Server system (DNS), or the DNS system may be slow. A timeout message may appear, or messages similar to the following may appear in the NetBackup detailed status log:
17:25:37.319 [12452.10360] get_vSphere_VMs: Processing vm 002-wcms 17:25:37.319 [12452.10360] get_vSphere_VMs: uuid 421a8b46-063d-f4bd-e674-9ad3707ee036 17:25:37.319 [12452.10360] get_vSphere_VMs: vmxdir [san-05] 002-wcms/ 17:25:37.319 [12452.10360] get_vSphere_VMs: datastore san-05 17:25:37.319 [12452.10360] get_vSphere_VMs: IpAddress 172.15.6.133 17:25:41.866 [12452.10360] get_vSphere_VMs: retry_gethostbyaddr for 172.15.6.133 failed with The requested name is valid, but no data of the requested type was found.
Note:
NetBackup may be unable to determine the host names of the virtual machines from their IP addresses (reverse lookup may fail).
To prevent browsing delays caused by DNS problems (Windows)
- On the Windows desktop of the backup host, click Start > Run and enter regedit.
- To be on the safe side, make a backup of the current registry (File > Export).
- Go to HKEY_LOCAL_MACHINE > SOFTWARE > Veritas > NetBackup > CurrentVersion > Config and create a key that is called BACKUP.
- Create a new DWORD under BACKUP, called disableIPResolution.
This registry key causes NetBackup to use the virtual machine's IP address as the virtual machine's host name.
- Use the NetBackup Browse for Virtual Machines screen to rediscover the virtual machines. The host names should now be the IP addresses.
To prevent browsing delays caused by DNS problems (Linux)
- On the Linux backup host, create (or open) the following file:
/usr/openv/netbackup/virtualization.conf - Add the following to the file:
[BACKUP] "disableIPResolution"=dword:00000000
This entry causes NetBackup to use the virtual machine's IP address as the virtual machine's host name.
Note: If the file already contains a [BACKUP] line, do not add another [BACKUP] line. Any other lines that already exist under [BACKUP] should remain as they are.
- Use the NetBackup Browse for Virtual Machines screen to rediscover the virtual machines. The host names should now be the IP addresses.
The following applies if: the in VMware Intelligent Policies is selected as and is enabled in the configuration setting.
In a large VMware environment, reverse name lookups can be very slow depending on the number of virtual machines being discovered. You can change the VNET_OPTIONS option to determine how many items NetBackup can cache. This value is in the bp.conf file on UNIX and Linux, and the registry on Windows.
The third value 200 is the default number of entries to be cached. Each entry takes about 1 kilobyte in memory. Available memory needs to be taken into account when you change this value. The maximum number of allowed entries is 100000.
VNET_OPTIONS = 120 3600 200 40 3 1 30 10 1793 32 0 0
Use the nbgetconfig command to view the configuration settings. Use nbsetconfig to change the settings.
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