[2026] in SIPB-AFS-requests
Power layout in machine room
daemon@ATHENA.MIT.EDU (ghudson@MIT.EDU)
Sat Jun 10 22:17:05 1995
From: ghudson@MIT.EDU
Date: Sat, 10 Jun 95 22:16:50 -0400
To: star-maintainers@MIT.EDU
Next week, we will be cutting over some of the plugs in the machine
room to UPSs. On the 25th (during the power outage), if we can be in
the machine room, we may consolidate the Decstation CPU plugs onto a
single power strip and put their disks on the UPSs.
The power arrangement in the machine room has gotten to be a little
bit of a mess, and I believe that this stems from our philosophy of
"compress all the plugs onto as few power strips as possible and add
power strips as we need more plugs". In particular, we have single
machines whose plugs range across two or more power strips, and
consequently each power strip powers more services than necessary. So
manipulating power strips is harder, and power cords tend to be
attached to power strips farther away from the machines than we'd like
them to be.
Since we're modifying the power arrangement anyway, we can leave more
room for expansion at the expense of using a few more power strips.
According to my currently favored plan, we would allocate one power
strip for each of the following (each UPS can hold four power strips):
* UPS 1: charon and 18.70 repeater (three plugs)
* UPS 1: anxiety-closet and 18.181 repeater (two plugs)
* UPS 1: penguin-lust (two plugs)
* UPS 1: bloom-beacon (four plugs)
* UPS 2: senator-bedfellow (five plugs, eight-plug strip)
* UPS 2: ronald-ann's disks (four plugs)
* UPS 2: rosebud's disks (two plugs)
* UPS 2: picayune's disks (two plugs)
* no UPS: the three maxine CPUs
This requires nine power strips, leaves 29 well-distributed power
slots open (26 on the UPSs), and leaves four plugs open on four power
strips (two on each UPS) so that we could add a new machine with up to
three disks without distributing its power across different power
strips (plus we can move repeater power without causing an outage, and
charon is going away which will leave one power strip with nothing but
a repeater).
I have removed one power strip from dkk's drawer so that we could plug
anxiety-closet into a UPS during tonight's work. This leaves us with
seven power strips in the machine room and one in dkk's drawer (which
belongs to dkk, but I think he said we could buy it from him). During
the meeting, I or someone else will probably propose buying 2-3 more
power strips to make up the difference and leave us with one to two
spares.
