typo fix with root check in nginx module

Signed-off-by: Eric Wong <normalperson@yhbt.net>
query: avoid redundant calls to err_line()

Additionally, log redundant calls to err_line so we have a
chance at figuring out what is causing redundant calls to
err_line()
query: fix error reporting for _do_fsck_reset

Failed set_server_settings calls just die with errors, so we
need to track and log that to syslog.  We'll also report we had
a database error back to the client (but avoid propagating the
exact error message, in case there is any sensitive
information).
debian/control: sysstat contains /usr/bin/iostat

Signed-off-by: Eric Wong <normalperson@yhbt.net>
Filter the devices before we do an expensive sort.

Signed-off-by: Eric Wong <normalperson@yhbt.net>
mogstored: fix kqueue usage with daemonization

Calling Mogstored::HTTPServer::Perlbal->start() creates a kqueue
descriptor.  kqueue descriptors are invalidated across fork,
so we must avoid kqueue creation until after daemonization.

We continue starting non-Perlbal HTTP servers before
daemonization, as error reporting can be easier if stderr/stdout
are not redirected to /dev/null.

ref: http://code.google.com/p/mogilefs/issues/detail?id=72
Cc: to.my.trociny@gmail.com