SIGUSR1 or SIGINT error

[David Birnbaum]

Howdy,

We occassionally get the following error when running our nightly
backups:

  rsync error: received SIGUSR1 or SIGINT (code 20) at rsync.c(229)

This happens more on one or two machines than on any of the others.  We've
looked high and low to see if we're mistakenly sending these signals, but
nothing is that we can find.

Does anyone know what this might be from?  Is it the server or the client
that's complaining about the signal?

Thanks,

David.