Thanks, Paul.  If jack had not crashed, shouldn't rotter have continued to record?  Is there any way to establish why recording was interrupted?  This happened about a week after I had started recording on this system.

On Mon, May 23, 2011 at 4:06 PM, Paul Davis <paul@linuxaudiosystems.com> wrote:
On Mon, May 23, 2011 at 6:56 PM, Eric Steinberg
<eric.steinberg@gmail.com> wrote:
> Hi folks,
> I'm trying to build an audio logger, that can record from six different
> sources to separate files.  I've been using the program rotter, and I
> thought it was working but have discovered that jackd crashed and recording
> was interrupted.  Unfortunately this was not reflected by qjackctl, which is
> what I use to launch jackd.  The qjackctl display showed that jackd was
> running, right down to the flashing "RT", but when I tried to launch
> meterbridge it complained that the jack server was not running.  The
> instances of rotter that I launched were still running, but were making
> files of just a few bytes, with no audio in them.  Is this a bug in
> qjackctl?  I am using Arch, on a Pentium 4, and using a firewire interface
> (Edirol FA-101).

you should use:

  ps aux | grep jackd

to establish whether jack has "crashed".

my guess is that had not crashed, but was no longer accepting new
clients and was otherwise hosed.