John R Pierce wrote: > On 6/9/2016 1:16 PM, m.roth at 5-cent.us wrote: >> That's what "middle of the night maintenance window" is for. > > in today's 24/7 global business world, there is no middle of the night, > its midday *somewhere*. > You pick the least buy day/time. For example, when I was supporting the City of Chicago 911 system, 16 years ago, they'd let us schedule software upgrades for Mon night, between 02:00 and 06:00. Tuesday, and then Thursday, were second and third choice - that's when there were the least number of calls. And allow me to venture to suggest that life-or-death calls to a 911 ctr (the calltakers went back to cards during that time) wasn't more important than world-wide business.... Besides, if it's that big a business, management *really* needs to spring for a hot spare complete system, to deal with hardware outages, and there should be mirrored d/bs, and *those* could be taken down, copied, and then brought back online and all the transactions that had been done while it was down updated to the backup. mark