SUMMARY
VMware backup jobs "waiting on client data" may accumulate in the queue.
ISSUE
VMware backup jobs "waiting on client data" may accumulate in the queue, causing subsequent backups to fail.
This issue can be seen on VMWare 5.5, 6.0, and 6.5 environments when using vCenter. This issue will be more common when vCenter alone is added to the Unitrends as an asset without also adding the individual ESXi nodes in addition per recommendations. This issue may be more prevalent in either large environments with numerous VM backups running concurrently, especially when multiple appliances concurrently communicate with the same vcenter for backups as well as in environments where the vCenter virtual appliance or Windows vCenter implementation is low on resources.
RESOLUTION
To resolve this issue requires 2 steps.
1) Upgrade to release 10.1
2) In the appliance UI, under Configure > Appliances > Edit > Advanced > General Configuration, filter for the section title "vprotect" and then set the value of forceVDDK from 0 to 1.
CAUSE
This issue can occur due to a defect in VMWare's provided VDDK package for 6.5.0. VMWare's code fails to provide valid return results for Unitrends to notice indicating consolidation steps are processed. This is a defect effecting multiple backup vendors, not just Unitrends.
Unitrends update 10.1 allows forcing the use of VDDK 6.0.2 instead of VDDK 6.5.0 which does not contain this defect. Use of VDDK 6.5 remains the default as only a small percentage of customers are effected by this issue.
VDDK 6.0.2 is compatible with VMWare 5.5 - 6.5 implementations.
Downgrading the VDDK package used causes only a single feature depreciation: Backups of VMWare 6.5 guests using VDDK 6.0.2 will not support VMWare-side inline compression. This may cause a small increase in backup time in cases where compression was capable of being used. This only impacts vCetner and ESXi 6.5 configurations.
Once VMWare corrects the VDDK for 6.5.0 to eliminate this defect, Unitrends will release a product update to restore VDDK 6,5 functionality. We do not have an ETA from VMWare as of the release of Unitrends ROS 10.1.