Gluster users - Sep 2009 - Is glusterfs replication intended for hard drive failure

After reading all the emails about replication, I start to worry about hard
drive failure.  Let's say one hard drive fails and I replace it with a new
one.  According to the previous discussion, a file is auto-healed only if a
client accesses it.  I have a lot of files and it's unlikely that each file
will be accessed by some client in a short period of time, so those not
accessed will be left unhealed.  If the other hard drive dies, then all
these unhealed data will be lost.  Is that correct?  Then what's the right
way to deal with hard drive failure, or glusterfs is simply not designed for
network failures but assumes reliable underlying storage?

- Wei Dong