Posts by Mick the Mad Router

Cisco tells UCS owners they may have a screw loose – in the server chassis

Problem is - if you don't know the PEM is loose you only find out the hard way. And by then it's too late because all the servers have shut down because the power policy has been breached.

Of course - that assumes you don't have all six PSUs powered up - in which case you'll be Ok running on the remaining 3 (each PEM holds the connected for 3 PSUs).

Yeah - that would be me. To the best of my knowledge it was the first X-series install in Australia.

Fortunately the servers weren't in production - so it didn't matter that I lost two of the four PSUs I had connected - thus breaching the chassis power limits - when the PEM came out. A bit of a shock nonetheless - fortunately not literally since when the PEM comes out with a live power cable still connected to it it exposes mains voltage conductors.

There are in fact two screws that secure each PEM. One is accessible inside the chassis (after you remove the IFMs and the bottom fabric blanking plates) - but the other is accessible only from outside the chassis - which may mean having to unrack the entire chassis to tighten it. One being tight holds the PEM in just fine though.

In all fairness - the installation guide actually tells you about these screws if you're assembling the whole thing from parts - but you don't expect to have to do it when the chassis comes integrated from the factory. And whoever heard of RTFM anyway?

There are a few other interesting gotchas with early ship UCS-X as well. There's a specific way you need to upgrade the Fabric Interconnects BEFORE you connect the X-series chassis - otherwise Intersight will complain that you can't upgrade the firmware.

Still - new product always means new teething problems when you get it into the hands of the great unwashed.