VLog Filespec Optional. Writes all Integration Services package events to the log providers that were enabled when the package ...

VLog [Filespec]

Optional. Writes all Integration Services package events to the log providers
that were enabled when the package was designed. To have Integration Services
enable a log provider for text files and write log events to a specified text
file, include a path and file name as the Filespec parameter. If you do not
include the Filespec parameter, Integration Services will not enable a log
provider for text files and will write log events only to the log providers
enabled for the package at design time.