Summary
Question
For each file that is accessed by VBDA there is a matching event from mvagtsvc.exe for exactly the same file.
Process Monitor logs were filtered to include the events that take 2 seconds, and we can see this:
9:22:19,4308436 vbda.exe CreateFile \Device\HarddiskVolumeShadowCopy659\Install\7zip\7z1514-x64.exe SUCCESS
9:22:19,4326471 mvagtsvc.exe CreateFile C:\Install\7zip\7z1514-x64.exe SUCCESS
9:22:21,6396038 vbda.exe CreateFile \Device\HarddiskVolumeShadowCopy659\Install\backinfo\Bginfo.exe SUCCESS
9:22:21,6451960 mvagtsvc.exe CreateFile C:\Install\backinfo\Bginfo.exe SUCCESS
9:22:24,9470879 vbda.exe CreateFile \Device\HarddiskVolumeShadowCopy659\Install\symantec\CCS_Agent-11.0-V3-Windows\AssignNewPerm.exe SUCCESS
9:22:24,9687742 mvagtsvc.exe CreateFile C:\Install\symantec\CCS_Agent-11.0-V3-Windows\AssignNewPerm.exe SUCCESS
9:22:27,0559048 vbda.exe CreateFile \Device\HarddiskVolumeShadowCopy659\Install\symantec\CCS_Agent-11.0-V3-Windows\Get_FQDN.exe SUCCESS
9:22:27,0701393 mvagtsvc.exe CreateFile C:\Install\symantec\CCS_Agent-11.0-V3-Windows\Get_FQDN.exe SUCCESS
9:22:29,2168233 vbda.exe CreateFile \Device\HarddiskVolumeShadowCopy659\Install\symantec\CCS_Agent-11.0-V3-Windows\PortQry.exe SUCCESS
9:22:29,2177324 mvagtsvc.exe CreateFile C:\Install\symantec\CCS_Agent-11.0-V3-Windows\PortQry.exe SUCCESS
9:22:31,2212611 vbda.exe CreateFile \Device\HarddiskVolumeShadowCopy659\Install\symantec\CCS_Agent-11.0-V3-Windows\regxp.exe SUCCESS
9:22:31,2291214 mvagtsvc.exe CreateFile C:\Install\symantec\CCS_Agent-11.0-V3-Windows\regxp.exe SUCCESS
9:22:33,2290398 vbda.exe CreateFile \Device\HarddiskVolumeShadowCopy659\Install\symantec\CCS_Agent-11.0-V3-Windows\Setup.exe SUCCESS
9:22:33,2380738 mvagtsvc.exe CreateFile C:\Install\symantec\CCS_Agent-11.0-V3-Windows\Setup.exe SUCCESS
Mcafee AV is creating delays when accessing the filesystems.
Answer
Adding an exclusion for VBDA.exe in the McAfee exception list will stop McAfee from scaning all files, accessed by vbda.