Unrecoverable TSM for VE Hyper-V data mover backups

Content

Incremental forever backup for Microsoft Hyper-V virtual machines was introduced with IBM Tivoli Storage Manager (TSM) for Virtual Environments (VE): Data Protection for Microsoft Hyper-V (DP for Hyper-V) Version 7.1.1.0. The TSM version 7.1.1.0 backup-archive client is used as the data mover to perform these incremental forever backups. Due to logic errors in TSM versions 7.1.1.0 and 7.1.1.1, those backups can be incomplete and unrecoverable, even though no error messages are logged during the affected backup operations.

In addition, if you restore the potentially corrupted backup data, the restored data also may be incomplete and unrecoverable, even though the restore operations are reported as successful without any error messages. Note that portions of corrupted Hyper-V backups might be recoverable.

These problems are documented in APARs IT04831 and IT05734.

IBM instructs customers not to run incremental forever backups of Microsoft Hyper-V virtual machines with the TSM 7.1.1.0 or 7.1.1.1 data movers. Instead, use 7.1.1.2 or higher.

Releases affected
Tivoli Storage Manager for Virtual Environments: Data Protection for Microsoft Hyper-V version 7.1.1 when used with Tivoli Storage Manager Backup-Archive Client (data mover) version 7.1.1.0 or 7.1.1.1.

How to determine if your backups are affected
It is not possible to determine if all or part of a specific backup is affected. If you used the affected data mover to perform any incremental forever backup of Hyper-V virtual machines (either -mode=iffull or -mode=ifincr), then those backups should be considered affected.

Workaround
Revert to the full backup method used before the incremental forever functionality was available, using the Backup-Archive client.

1. Rename the Hyper-V license file to another name (if installed)
Default location is C:\Program Files\Tivoli\TSM\TDPHyperV, file name is tdp4hyperv.lic

2. Run a full VM backup with the Backup-Archive client
For example, on the command line, issue "dsmc backup vm <myvm> -mode=full"
where <myvm> is the name of the Hyper-V virtual machine

Fix and Instructions
The fixes for IT04831 and IT05780 are available in data mover (TSM Backup-Archive Client) version 7.1.1.2 or higher. The 7.1.1.2 version of the data mover is available as part of DP for Hyper-V version 7.1.1.2, which can be obtained from IBM Passport Advantage. If you have already installed DP for Hyper-V version 7.1.1.0, you can obtain version 7.1.1.2 from Passport Advantage or the FTP site. If you are installing DP for Hyper-V for the first time, you must obtain version 7.1.1.2 from Passport Advantage.

The 7.1.1.2 version of the data mover is not available as a stand-alone TSM Backup-Archive client download. However, because maintenance is cumulative, new versions (higher than 7.1.1.2) of the data mover that are made available for stand-alone download will also include the fixes for the problems described in this flash.

DP for Hyper-V media with the fixes will be available starting 12 December 2014, subject to change at the discretion of IBM.

Flash update history:
24 October 2014 - Original version published

31 October 2014 - Updated to indicate that customers are instructed to not use incremental forever backups for Microsoft Hyper-V virtual machines until a newly discovered issue is addressed.

12 November 2014 - Clarified that workaround uses the Backup-Archive client.

10 December 2014 - Updated the flash to indicate that a solution is available with DP for Hyper-V 7.1.1.2 and higher.