Log Message:
-----------
Add a note about GNU tar's propensity to complain if a file changes
while tar is copying it. This behavior is unhelpful when taking a base
backup. Per gripe from Pallav Kalva back in April.
Modified Files:
--------------
pgsql/doc/src/sgml:
backup.sgml (r2.72 -> r2.73)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/backup.sgml.diff?r1=2.72&r2=2.73)