Not sure what it is about APC

Back in November, I was inspired to blog about my experiences with an APC UPS.  Today, from the "I wish there was better documentation on this" department, I have another APC tale to tell.

A Quest for Redundancy

I really wanted redundant power for one of my switches, and really didn't see the need/value in replacing the switch with a model with dual power supplies.  This ultimately led me to an APC Automatic Transfer Switch (AP7750):

One input goes to each PDU in the rack, and the outputs power the single-PS gear (in this case my switch)  Easy-peezie.

Just like all of the other APC gear in the rack, it's got a network module.  Sweet.  Only problem is that it doesn't want to get an IP address on the network.  APC will ignore any DHCP leases without a "cookie" in the DHCP options, and I don't really feel like messing with DHCP just for this one-off.  I figured that using the included "device IP Configuration Wizard" would find the device and let me IP it.  Not so much.

Found it.  Now What?

The tool  scanned the network and found the MAC address.  Good.  I entered the IP/netmask etc and... "The IP is already in use on the network"  Er... No it isn't...  Some Googling suggested that a newer version the utility was available at apc.com... Yup.  Much they're up to v5.x (vs v3.x on my included CD).  The GUI is a bit snazzier too... and... it fails with a different error, but still the same problem.

When in doubt, bust out a shell

I'm pretty certain that I had to go through this once before with one of our APC PDUs or freestanding UPS'es (a while ago) which helped me to find the solution more quickly... the trick is to send a specially crafted ping to the device:

1. arp -s <desired IP> <mac address of APC device>
2. ping -s 113 <desired IP>
3. (while the ping is still running, in another window) telnet <desired IP>  u/p: apc/apc
4. Configure networking on the device properly (netmask/gateway, etc)

RTFM?

I will admit that this is kinda documented in the APC install guide (in a section that perhaps should have been labled "Beware the Leopard"), though it only worked for me when I followed the exact steps above (113 byte ping running while simultaneously attempting to telnet to the APC CLI).


Hopefully this is helpful to someone, someday.

Why buy a sled?

So I have a couple of 1kVA rack mounted APC UPS'es (APC Smart-UPS 1000VA).  We got them for our MDF, while in the midst of a build-out, before the "big UPSes" were moved/installed in the new space.  They worked really well and were already in the racks, so we never bothered to run the main UPSes to these racks... they stayed on generator-backed emergency power, nicely doing their job through multiple power outages.

Recently, I was greeted by the beep-beep-beep'ing of a "your batteries are dead" alert from one of the units.  Okay, it's been four years... I can't really expect more than that from a UPS... let's order some new batteries...

Googling the part # of the UPS, I get two kinds of results.  One for an RBC23 runs between $150-$300 (APC compatible vs OEM, etc) and looks like this:

Okay... looks like a "four pack" sitting in a sled/tray... fair enough.  The other results look like this:


and run about $75 for 4 of them (APC compatible) with no included sled/tray.  Seems kind of a pricey piece of sheet metal and a couple of pieces of wire... Why not just re-use the sheet metal that I already have?

Factor in the cost of band-aids

Pulling the existing tray out of the unit is effortless (okay, it's heavy... but it's nice that you don't need to remove the UPS from the rack).  That was where the effortless part ended.  The sled seemed to be designed by some kind of sadist with a razor blade fetish.  I needed to handle the sled quite a bit to force the batteries (which were held firmly in place with double-stick tape) out.  Heavy object with sharp edges.  What could possibly go wrong?

Hope the Batteries haven't started to leak

The first UPS's batteries were still in decent shape (the UPS wasn't in an alarm state yet), and this was reflected in the physical condition of the batteries.  Maybe a little dust, but otherwise the only problems that I encountered were from handling the sled.  The second UPS had been under considerably more load, and was the one beeping that it needed new batteries.  The inside of the sled was pretty impressive.  Let's just say I'm glad that I had some alcohol handy to clean things up inside.  Could have been a lot worse, but also could have been a lot better.  Quick test.  Try to guess which battery was taken from which UPS:

Of course the fact that the batteries had deformed meant that it was even tougher to get them out of the sled.  Let's just say that some brute force (10lb dumbell and large screwdriver) and ultimately some more band-aids got the job done.  Some more clean-up on the connectors and everything is humming along nicely again.

Was it Worth It?

I hate paying more (or almost as much) for consumables as for the product itself.  Maybe it's a personality flaw of mine, but there you go...  I think that if these UPS'es are still in service in 3-4 years I'll pony up for new sleds... if for no other reason than I don't know how many connect/disconnect cycles the sled's wire harness battery connectors really have in them.  I guess I need to add "leather gloves" to my list of things to keep in the MDF.

Inspired by xkcd

So I was reading xkcd, and read this:




and thought it was funny, and chuckled a bit. And then thought about it a bit... obviously I can relate... I spend a fair amount of time googling for ...something... and yet--at least compared to back in the Usenet days (I guess I'm old) I don't spend nearly enough time contributing answers back.

Part of it is that rather than the EXACT scenario above, I find myself searching (forums, mailing lists, etc) various threads, documentation etc and NEVER post at all...

Some of this is due to the number of forums (etc)... that require sign-ups to post.  After spending hours figuring out the problem, I'm not going to care enough to dig though each dead-end (or incomplete) leg of the search to find the threads that (incompletely) discussed my problem and reply with my solution.

And yet... it seems like--somehow--I should at least try to contribute to the Wisdom of the Ancients

So... I'll start a blog.  No promises on how often I'll update it... or how well... or with what (though I'll try to refrain from politics and pictures of my kids)  The beauty of the Internet is if there's anything worth archiving, Google will index it... and maybe someone... someday... will have an answer to their question.