Notes on setting up a Sentry Power Tower XL networked PDU.

Wow, been a while.  No explanation, no apologies.

Anyway.  Spent about a day working on trying to get the Sentry Power Tower XL working with powerman.  I'm not declaring victory here, because I still haven't got powerman working.  But I'm much farther along, and I got sufficiently annoyed at the lack of documentation to rant at Luke, whose remark was "you can fix this."

So.  Documentation on controlling the Sentry/Servertech Power Tower XL via SNMP, as written by someone who's never used SNMP before.

First, set up the box so that you can connect to it.  I used a Cisco-pinout RJ45 serial cable, 9600 8n1.  Power it up, sign in with the default username and password (admn/admn).  If necessary, reset the firmware by holding in the reset button next to the LCD on the front.

(Some notes: "front" is the side with all the plugs, regardless of how you actually choose to mount it.  Also, the reset button is an unlabeled pinhole.)

The online documentation on resetting was a little inaccurate, at least for the firmware version I originally had.  Nothing will happen when you initially push the button.  Hold down the button until the display changes to 3 horizonal lines, then release.  The display will change to one pair of horizontal lines in the middle of the display.

Now that we can log in, we need to upgrade the firmware.  The mechanism is pretty clever.  The box includes an ftp client that can download the firmware from a remote host and install it.  (It also includes an ftp server, apparently, but that's unrelated.)  We ran into trouble because we're on a masq'd network that doesn't allow active FTP.  If you don't have this problem, you can tell the box to download the firmware from .

We downloaded the firmware locally and set up a quick FTP server.  Whatever.

Either way, set the ftp settings as appropriate.  Our settings are as shown:

Sentry: show ftp                                                               
   FTP Client Configuration                                                    
      Username:   prgmr                                                       
      Password:   ******                                                       
      Directory:  Downloads/                                                   
      Filename:   mrrpm-v53s.bin                                               
   FTP Automatic Update Configuration                                          
      Automatic Updates:  Disabled                                             
      Scheduled Day:      Everyday                                             
      Scheduled Hour:     12 AM                                                
   Command successful              

Then issue a 'restart ftpload'.  The box will download and flash its firmware.

Cool. Now you have a fully armed and operational Sentry Power Tower XL.  (Incidentally, much of this probably also applies to the Switched CDU.)

SNMP is going to be a little tougher, especially if you've never used it.  I had to install the appropriate software (on Ubuntu, apt-get install snmp worked fine.).  Then I had to download MIBs, which translate the numeric keys returned by snmp into human-readable values.  To do this:

 * download mib file: wget
 * copy mib file to snmp's search path: cp Sentry3.mib /usr/share/snmp/mibs
 * specify that you want to use this file: I did this by adding a "-m +Sentry3-MIB" to my snmp commands.  There are better ways.  Note that you use the name listed in the file, not the filename itself.

Now you should be able to get useful information.  Try:

$ snmpwalk -v2c -c public -m +Sentry3-MIB

This should give you a long list of keys, including stuff like power usage.  Congratulations.

You should also be able to control the outlets.  This was where I got extremely annoyed and started ranting, because I had to resort to guessing magic numbers to figure this out.  There's probably some documentation somewhere, but I couldn't find it.  To spare you the trouble:

The OID you want is: Sentry3-MIB::outletControlAction.1.1.<outlet number>

The magic numbers are: 1 (on), 2 (off), 3 (reboot).

In our case, the approriate invocation to reboot outlet 4 was:

$ snmpset -v2c -c private -m +Sentry3-MIB Sentry3-MIB::outletControlAction.1.1.4 i 3

That's the translated OID, "i" for integer, and the value we want to set, "3".

Now to actually figure out how to put powerman in front of this.


note, if you have a 'b' slave unit, it's a little different.

snmpwalk -v2c -c private -m +Sentry3-MIB iso

will give you something like:

Sentry3-MIB::outletName.2.1.7 = STRING:

Sentry3-MIB::outletID.2.1.7 = STRING: B7

so to reboot, you use the

snmpset -v2c -c private -m +Sentry3-MIB Sentry3-MIB::outletControlAction.2.1.7 i 3

also note, it will whine forever....

lsc@beholder:~$ snmpwalk -v2c -c public -m Sentry3-MIB
MIB search path: /home/lsc/.snmp/mibs:/usr/share/mibs/site:/usr/share/snmp/mibs:/usr/share/mibs/iana:/usr/share/mibs/ietf:/usr/share/mibs/netsnmp
Cannot find module (SNMPv2-SMI): At line 9 in /usr/share/mibs/netsnmp/Sentry3.mib
Cannot find module (SNMPv2-TC): At line 10 in /usr/share/mibs/netsnmp/Sentry3.mib
Did not find 'enterprises' in module #-1 (/usr/share/mibs/netsnmp/Sentry3.mib)
Did not find 'DisplayString' in module #-1 (/usr/share/mibs/netsnmp/Sentry3.mib)
Unlinked OID in Sentry3-MIB: serverTech ::= { enterprises 1718 }
Undefined identifier: enterprises near line 155 of /usr/share/mibs/netsnmp/Sentry3.mib
Cannot adopt OID in Sentry3-MIB: events ::= { sentry3Traps 0 }

unless you

sudo apt-get install snmp-mibs-downloader

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This page contains a single entry by chris t published on February 26, 2012 9:47 AM.

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