It's been a miserable week for lock acquisition, with each night worst than the last. The nadir was around Sunday night, when I couldn't even get a PRM to lock stably, which meant that the auto-alignment scripts could not finish successfully. It now appears that was due to some XYCOM mis-settings.
We've also been having problems with timing for c1susvme2. Attached is a one-hour plot of timing data for this cpu, known as SRM. Each spike is an instance of lateness, and a potential cause of lock loss. This has been going on for a quite a while.
Tonight we also encountered a large peak in the frequency noise around 485 Hz. Changing the MZ lock point (the spot in the PZT range) solved this.