IT11599: ANS4308E RC=4388 ON MICROSOFT HYPER-V GUEST BACKUP BECAUSE OF INCORRECT VHDX FILE SIZE

IBM Spectrum Protectâ„¢ Client 7.1.6 Downloads and READMEs

APAR status

• Closed as program error.

Error description

• The backup of a Microsoft Hyper-V guest might fail with the
  following error :
  
  ANS4308E Full VM backup of 'Hyper-V' Virtual Machine '<guest
  name>'
           failed with RC=4388 mode=Incremental Forever -
  Incremental,
           target node name='<target node name>', data mover node
  name='<data mover node name>'
  
  The symptom is seen when the guest disk size is not a multiple
  of the default vhdx block size of 32MB.
  The ?BlockSizeBytes option is only available in the Microsoft
  Powershell command and only at VHDX creation time.
  The Microsoft Hyper-V manager GUI uses only the default 32MB
  blocksize at VHDX creation.
  An indicator that this problem is seen is given in the 'backup
  VM' output message :
  For example :
  Processing snapshot
      disk:         c:\ClusterStorage\Volume2\HyperV\Virtual Hard
  Disks\<guest name>.vhdx (Hard Disk 1)
      Capacity:     52,444,385,280
      Data to Send: 52,445,577,216
      Transport:    LAN[sending]
  
  Observe that the "Data to Send" bytes is bigger than the
  "Capacity".
  
  Tivoli Storage Manager Versions Affected: Tivoli Storage Manager
  for Virtual Environments - Data Protection for Microsoft Hyper-V
  
  Initial Impact: Medium
  
  Additional Keywords: zztsm tsm4ve Hyper-V hyperv Hyper_V VHDX
  ANS4169E
  

Local fix

• The work around for already existing VHDX disks is to adjust the
   guest disk size to be a multiple of the blocksize. For example
  increase the VHDX to a multiple of 1GB.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * Tivoli Storage Manager for Virtual Environments component    *
  * Data Protection for Microsoft Hyper-V versions 7.1.1, 7.1.2, *
  * 7.1.3 and 7.1.4 running on all Microsoft Windows x64         *
  * platforms                                                    *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * See ERROR DESCRIPTION                                        *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * This issue is projected to be fixed in the Tivoli Storage    *
  * Manager Client on Windows 7.1.6                              *
  * Note 1: The Tivoli Storage Manager (TSM) Client is a part of *
  * the Data Protection for Microsoft Hyper-V. In Data           *
  * Protection for Microsoft Hyper-V environments, the TSM       *
  * Client is also known as the data mover.                      *
  * Note 2: This is subject to change at the discretion of IBM.  *
  ****************************************************************
  

Problem conclusion

• Virtual disks are now correctly backed up when their size is not
  multiple of block size.
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Modules/Macros

• dsmagent dsm
  

Fix information

• Fixed component name

  TSM CLIENT

• Fixed component ID

  5698ISMCL

Applicable component levels

• R71W PSY

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