Recreating archive_status

[Simon Riggs <simon(at)2ndquadrant(dot)com>]

During recovery procedures, there is a step that says

"If you didn't archive pg_xlog/ at all, then recreate it, and be sure to
recreate the subdirectory pg_xlog/archive_status/ as well."

If you forget to do this, you may not realise until the recovering
server comes up and tries writing to the directory. The message that is
spat out when this happens is 

LOG:  could not create archive status file
"pg_xlog/archive_status/00000001000003CE0000009E.ready": No such file or
directory

We could check this just as the server comes up and then re-create it if
necessary. So we have one less step in the process to remember. Existing
scripts which perform this automatically will not need changing.

We can keep the message in case something removes the directory later.

Views?

-- 
  Simon Riggs
  2ndQuadrant  http://www.2ndQuadrant.com