A restore of a VM with the hotadd transport mode or the SAN transport mode may not succeed because of a metadata issue

A restore of a VM with the hotadd transport mode or the SAN transport mode may not succeed because of a metadata issue

Article: 100010613
Last Published: 2018-12-05
Ratings: 0 1
Product(s): NetBackup

Problem

A restore of a VM with the hotadd mode or the SAN transport mode may not succeed if the VM’s disk geometry in the backup image differs from the VM’s default values. VM disk geometry refers to the layout of the virtual disk (cylinders, heads, sectors) as specified in the vmdk file.

Note: The restored VM may not be able to start. VMware has documented the cause of this issue in their VDDK 5.1, 6.0 and 6.5 release notes, under Known Issues and Workarounds: "Metadata write is not supported for HotAdd and SAN transport."

www.vmware.com/support/developer/vddk/VDDK-510-ReleaseNotes.html
www.vmware.com/support/developer/vddk/vddk-600-releasenotes.html
VDDK 6.5 Release Notes

Error Message

The NetBackup restore job reports partial success with status code 1 (the requested operation was partially successful). The Activity Monitor job details indicate the metadata values that need to be set manually. For example:

09/05/2013 15:06:58 - begin reading
09/05/2013 15:07:52 - Info tar (pid=25893) INF - Transport Type = hotadd
09/05/2013 15:07:52 - Warning bpbrm (pid=25848) from client acmevm2.com: WRN - Cannot set metadata (key:geometry.biosHeads, value:16) when using san or hotadd transport.
09/05/2013 15:07:52 - Warning bpbrm (pid=25848) from client acmevm2.com: WRN - Cannot set metadata (key:geometry.biosCylinders, value:83257) when using san or hotadd transport.

In this example, the non-default disk geometry values are geometry.biosHeads, value:16 and geometry.biosCylinders, value:83257. NetBackup is unable to write these values in the vmdk file of the restored VM.

Solution

If the VM starts up, no action is required. If the VM does not start, try one of the following:

  • Rerun the restore with the nbd or nbdssl transport modes.
  • Or manually set the correct disk geometry for the restored VM by editing its vmdk file, as follows:
  1. Download the restored VM’s vmdk file from the datastore.
  2. Open the vmdk file in a text editor and locate the existing ddb.geometry entries in the file.
  3. Use the ddb.geometry format to add the disk values that are listed in the NetBackup detailed status. For the above example, enter the following:
    ddb.geometry.biosHeads = "16"
    ddb.geometry.biosCylinders = "83257"
  4. Group all disk ddb.geometry entries together. The following VMware Knowledge Base article describes the entries in a vmdk file:
    https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1002511
  5. Save and upload the vmdk file to the datastore.

 

 

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