OK, cool. I did not want to be in a position where I stop the servers, pg_upgrade --link 9.1 to 9.2, then (eventually) pg_dropcluster of 9.1 and, woops, I killed all of my data files.
On Wed, Jul 10, 2013 at 12:02:06PM -0700, Wells Oliver wrote: > Hard linking means that you must maintain 8.2's data directory though, even > after upgrade, correct? Since it's a link and not a copied file. >
I think it only hard links the files to the new 9.2 data directory so you can delete the old data directory and the files will still be in the new directory since the link count will be > 0.