Hot Copy or restore failures may result from Hyper-V synthetic backups when non-default deduplication block size is used

SUMMARY

Hot backup copy failures may result from invalid synthesized backups.

ISSUE

This issue is exceedingly rare.  To encounter this issue, one first must be using a non-standard Hyper-V deduplication block size setting.  
If in the appliance master.ini file the value maxSubfileBytes_Hyper-V is not present, then the default values are being used and this issue issue does not apply.  




 

RESOLUTION

If you are using a custom hyper-V backup block size for deduplication set using [fileDedup] maxSubfileBytes_Hyper-V, upgrade your appliance to version 10.1 and perform new Hyper-V full backups of any effected synthetic backup.