Care to elaborate on that? I haven't seen issues with the two mechanisms I know of in NT:
1. CreateFile with FILE_APPEND_DATA
2. WriteFile with the OVERLAPPED offset set to ~0
Both of these get you writes that are as far as I know safe to have multiple processes writing to a common log file. Not sure about flushes to disk but you could probably get away with FlushFileBuffers for this.
NTFS handles append just fine. As another comment speculated, the parent may have meant NFS, which does notoriously have lots of problems with append, and many other POSIX semantics.
Care to elaborate on that? I haven't seen issues with the two mechanisms I know of in NT:
1. CreateFile with FILE_APPEND_DATA
2. WriteFile with the OVERLAPPED offset set to ~0
Both of these get you writes that are as far as I know safe to have multiple processes writing to a common log file. Not sure about flushes to disk but you could probably get away with FlushFileBuffers for this.