iridium, the current production Phabricator server, is on trusty

we want to rename it from iridium to phab1001 and install jessie.

there is already phab2001 in codfw and it has jessie and the puppet role now works on jessie,
since today we closed T139475

this means we also have real labs testing now, with a jessie instance using the regular main prod puppet role, not a "labs" role or manual setup.

one way to achieve this could be to make phab2001 the actual production server first (T137928), this should also be unblocked now since T143363 has been resolved). so to first resolve that and switch over to codfw and while traffic is there reinstall iridium

or another way would be to schedule a maintenance window and take phab down and upgrade it to jessie before phab2001 is done, without switching anything to codfw yet

the longer term goal is of course to have both up on jessie as phab1001/phab2001, first one as a simple warm standby and longer term get into real phab clustering support