#!/usr/bin/perl -0p
s#^( *filter) = .*#$1 = [ "r|/dev/mapper/xenvg-.*|" ]#m or die;
s/^( *locking_type) = 1.*$/$1 = 3/m or die;
s/^( *retain_min) = .*$/$1 = 2147483647/m or die;