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Date: Mon, 28 Sep 2015 17:23:08 +0200
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Subject: Downtime (was Re: Problems with ZFS file servers)
From: Jonathan McKeown <jonathan@scatterlings.org>
To: Bob Healey <healer@rpi.edu>
Cc: freebsd-questions@freebsd.org
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So your employers prefer unplanned downtime to scheduled maintenance? That,
IMHO, is.... unwise.

Here's an alternative take. I also worked as a sysadmin in academia (until
being medically boarded with chronic illness). We have a 14-hour Major
Maintenance Window from 17h30 through to 07h30 on the next morning on the
1st working Tuesday in January, and 1st Tuesday of each other month - which
is non-negotiable - and a minor maint window for the same times on all
remaining Tuesdays, which can be rescheduled.

Not all the windows (nor all the hours in each window) are used but
everyone knows they might be and plans accordingly (and a few days' advance
warning is given of maintenance, with estimated outage times and durations).