A while after we first began using MythTV here, we had some recording glitches with multiple streams going simultaneously.

The cause was the code performing "fsync()" after each measly tiny write. At worst, it ought to have been using "fdatasync()" instead. At best it shouldn't have been doing either, instead leaving the decision to the operating system.

As a temporary workaround, I just commented out the unnecessary fsync/fdatasync calls. MUCH improved. And since then, a MythTV developer checked in with us on one of the kernel mailing lists, and an even better and more modern solution using "sync_file_range()" was discussed and implemented.

It's quite good, now.

Cheers