DreamHost runs a procwatch script on shared servers that kills any process that uses more than a certain (unspecified) amount of server resources. I just watched in
top -c as the
php53.cgi process running my backup job suddenly became
<defunct> in the middle of the job.
This has been causing incomplete backup archives to be created.
I think BackWPup could use a "nice" mode that, when enabled, splits the backup job into small pieces that can be done separately and in under 10 seconds each (or some other safe threshold).