Lessons Learned: Rack Enclosures: PDUs, PDU Cables, and Cable Ties

This is what one of our Proof-of-Concept (PoC) rack enclosures looked like before we were finished buttoning things up:


Four Node Storage Spaces Direct Cluster with Mellanox 40GbE RoCE Fabric

In the end, we did a decent job of wrapping and coiling the massive 40GbE cables and the 250V PDU cables.

Switched ZeroU PDU

The PDU is an APC Switched ZeroU AP8941 that allows us to power individual outlets or set up groups of outlets.


APC AP8941 Home Page

All of our servers have Intel RMM, Dell iDRAC Enterprise, HP iLO Advanced, or the built-in RMM in our Tyan based systems.

While the RMMs offer out of band management and KVM/IP access to the console, if something hiccups with the server board the RMM can go offline which then requires power to be fully removed.

So, we have that base covered.

Drain the node, shut it down, flip the outlets to OFF in PDU management, wait a few minutes, then power them back on.

Locking PDU Cables

Now, on to another important lesson: Locking PDU cables!


APC Locking PDU Cables

Why should we use locking PDU cables?

Because, when working around the back of the rack, which means in the heat, we sometimes bump those cables and sure enough, they come loose or outright fall out!

For obvious reasons this situation is bad.

We tried a shim kit for the PDU end of the cable but that turned out to be a real Mickey Mouse affair.

The above cables arrived yesterday.

We should have enough to cable up the entire rack.

Cable Ties

Ever notice that data cable VELCRO based ties are quite expensive? Well, the ones designated for plants (previous post) are quite inexpensive.

We have a number of rolls of heavy duty VELCRO tie for those large bundles where more holding power is required.

We’ll post some pics once the setup is complete.

Thanks for reading!

Philip Elder
Microsoft High Availability MVP
www.s2d.rocks !
Our Web Site

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