Restore shows VDDK DiskChainDBGet errors despite Restore OK status

Bacula Enterprise Only

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In some cases, restore job logs can show the following messages even though the job ends with an OK status:

2026-02-07 16:43:34 xxx-fd JobId 3691231: W:07-Feb-2026 16:42:12 vddk: vddk.c:157-0 2026-02-07T16:42:12.937+01:00 error -[814642] [Originator@6876 sub=DiskLib] DISKLIB-CHAIN : DiskChainDBGet: Cannot apply logicalSectorSize to partial chain.
2026-02-07 16:43:34 xxx-fd JobId 3691231: W:07-Feb-2026 16:42:12 vddk: vddk.c:157-0 2026-02-07T16:42:12.937+01:00 error -[814642] [Originator@6876 sub=DiskLib] DISKLIB-CHAIN : DiskChainDBGet: Cannot apply physicalSectorSize to partial chain.

These messages are generated by VMware, not directly by Bacula. In general, Bacula reports responses received from VMware to provide visibility into unexpected situations. In this particular case, he messages are usually harmless and are more commonly seen when using the VDDK HotAdd transport mode.

The messages indicate that the disk snapshot chain is incomplete while metadata is being propagated. This is common and generally harmless in HotAdd-based restores. It can also occur with NBD, although much less frequently. With HotAdd, the restored disk is newly attached to the proxy, and chain resolution is handled by the VDDK library rather than by ESXi.

As a result, the VDDK library may initially be unable to find the proper disk chain, causing these messages to be logged. VDDK then reconstructs the required metadata chain internally.

In this kind of situations, it is recommended to check the restored host status after the restore completes to ensure that it is fully functional.

If these messages occur frequently and the system administrator wants to eliminate or reduce them, NBD transport mode can be prioritized for restores by setting the vddk_restore_transport_mode to a value such as: “nbdssl:nbd:hotadd”.