In the message dated: Thu, 13 Aug 2009 16:58:03 EDT,
The pithy ruminations from Allan West on 
<[lopsa-discuss] automatic transfer switch for single power supply gear> were:
=> I've got some single power supply equipment (Cisco switches) in a rack
=> with PDUs which have 120V C13 receptacles. I'm looking for an automatic
=> transfer switch which I can plug into a C13 receptacle on either side of
=> the rack, and feed the single power cables so that either side of the
=> rack's power can be removed while the switches stay up.
=> 
=> Can anyone recommend something which fits this niche? I'm not at liberty

Sort of.

I'm using a TrippLite PDUMH15ATNET PDU. It does what you want, and also has an 
LED showing amperage, and is IP accessible to configure and power up/down the 
outlets.

Sounds nifty? Well, it would probably meet your requirements just fine. 

However, I bought it for use as both a transfer switch (for items like network 
gear, KVM, etc. that have just one power supply) and for use as a "fencing 
device" for an HA cluster. [A power fencing device is a method-of-last-resort 
to forcibly shutdown cluster nodes in case of a logical inconsistency. This is 
to prevent multiple nodes from writing to the same storage and causing data 
corruption.]

The servers that make up our HA cluster already have 2 powersupplies, so the 
TrippLite PDU is used as an out-of-band method to shutdown the servers via 
"fencing"...essentially giving a command to remove power from both 
powersupplies.

<RANT>
The TrippLite PDU is unacceptable as a cluter fencing device for one reason: 
there is no way to shutdown multiple outlets on the PDU simultaneously. The 
shutdown command, as run on the PDU, inserts a random delay (observed to be 
about 15~35 seconds). This is a significant delay in a device that's intended 
to prevent data corruption by preventing multiple machines from acting as if 
they are the master nodes in the cluster.
</RANT>

As a network-accessible PDU and transfer switch...it's fine.

Mark 

=> to run new PDUs in the rack, nor do I have access to 208-204V
=> receptacles to feed an automatic transfer switch, which seems to be the
=> most common solution offered by APC, etc.
=> 
=> There are a few items listed on reseller sites, but they don't all lead
=> to current products available from the listed vendor. I'd prefer to find
=> something which is actually recommended and in use by a colleague.
=> 
=> Thanks, Allan
=> _______________________________________________
=> Discuss mailing list
=> [email protected]
=> http://lopsa.org/cgi-bin/mailman/listinfo/discuss
=> This list provided by the League of Professional System Administrators
=>  http://lopsa.org/
=> 



_______________________________________________
Discuss mailing list
[email protected]
http://lopsa.org/cgi-bin/mailman/listinfo/discuss
This list provided by the League of Professional System Administrators
 http://lopsa.org/

Reply via email to