VM disk restore using san transport VixDiskLib_Write calls fails

Products

• VMware Aria Suite

Issue/Introduction

Symptoms:
During VM disk restore, using san transport VixDiskLib_Write calls might fail.

You might see these additional symptoms:

• Thick eager zeroed disk is zeroed out when it is created. 
• Thick lazy zeroed disk is zeroed out when new data is written to it.
• When you perform a full vm restore, the disks are used and are already allocated.
• If a new disk is created, only thick eager zeroed provision type will allocate the disk at that time.
• You see error messages similar to:

[Error Messages]
San transport error: Unspecified error.
 DISKLIB-LIB : RWv failed ioId:
 VixDiskLib: Detected DiskLib error 318 (Unknown error).
 VixDiskLib: VixDiskLib_Write: Write 512 sectors to disk at 0 f
 vddksdkPrintVixError(): VM name
 VMware vStorage API error for virtual machine
 TSM function name : VixDiskLib_Write
 TSM file : ..\..\common\vm\vmvddksdk.cpp
 API return code : 1
 API error message : Unknown error
<========= Exiting vddksdkWrite()

Note: This error might be intermittent. However, overall the disk restored is corrupted.

Resolution

This is a known issue affecting VMware VDDK for vSphere 6.0. 
Currently, there is no resolution.

Workaround:
To work around this issue, create a disk with Thick Provision Eager Zeroed option.

Note: VMware strongly recommends to choose Eager Zeroed Provision when using san mode.