> [!LockFileCreateSync] > <table><tr><td rowspan="4" width="25%"><img src="assets/wl_io_lockfilecreatesync.png"></td><td><b>Wait Category</b></td><td>IO</td></tr><tr><td><b>Mechanism</b></td><td><code>CreateLockFile</code></td></tr><tr><td><b>Operations</b></td><td><a href="Operations/Table/SeqScan">SeqScan</a></td></tr><tr><td><b>Resources</b></td><td><a href="Resources/disk IO">disk IO</a>, <a href="Resources/CPU">CPU</a></td></tr><tr><td colspan="3"><b>Runtime Authority Durability Barrier</b>. To prevent a race condition where a second Postgres instance might start because the first one's lock file hadn't yet hit the disk, the engine forces a physical sync of the <code>postmaster.pid</code> file before proceeding with the rest of the startup sequence.</td></tr></table>