Archive: 2010

SNMP GET Errors in OpsMgr EventLog

I’ve been building a little SNMP Management Pack in the past few days to discover and monitor a bunch of PowerWare UPS’s, which turned out to take quite a lot more energy and time than expected. Mostly due to the facts that I am really bad with SNMP and how it works, I’ve never really looked into the inner working of building an SNMP management pack and also because we ran into a couple of errors preventing the discovery process to work alright. To make it clear right away, this is not going to be a “Building an SNMP Management Pack Tutorial” since there’s plentiful good ones out there already, and to be extra helpful I’m gonna include a few links right away: SNMP Setup and Simple Custom SNMP Discovery - Pretty much the basics SNMP Management Pack Example: NetApp Management Pack - Part 4 actually, but has the links to the other parts Creating SNMP Probe Based Monitors - No custom discovery, but a good and simple guide to SNMP Probes It’s the second, the NetApp one, I’ve used as a guide to building the UPS management pack since it goes through the process of building your own filtered discovery using SystemOID to identify your hardware-classes and then building the monitors on top of those. Let’s get to it When building the discovery of my hardware classes I ran into problems. The discovery simply did not work. At first I got some strange errors about “invalid queries”, something that turned out to be related to me reading two guides–seriously though, pick one guide that is closest to what you want to achieve and stick to it–and mixing up the XPathQuery variables. Silly me. I got those errors to go away and I was able to get a few objects to my base-class, but none of the hardware classes who was populated through the return value of an SNMP OID got discovered. The only error I got this time was the following: Log Name: Operations ManagerSource: Health Service ModulesDate: 2010-09-02 11:19:12Event ID: 11001Task Category: NoneLevel: ErrorKeywords: ClassicUser: N/AComputer: CENSOREDDescription:Error sending an SNMP GET message to IP Address XX.XX.XX.XX, Community String:=CENSORED, Status 0x6c.One or more workflows were affected by this.Workflow name: CENSORED.MP.CLASS.DISCOVERYInstance name: CENSORED_DEVICENAMEInstance ID: {5C7EFB30-D885-8843-0DD7-EA86B4FD2311}Management group: CENSORED I went through all the other logical steps of troubleshooting an error like that which include double-checking firewall settings, OIDs, IP-addresses, allowed hosts and so forth. It wasn’t until I loaded the PowerMIB into a MIB Browser installed on the proxy machine (in this case a Management Server) I realized that there was no problem sending an SNMP GET to the UPS from that server. I launched Wireshark and had it listen to SNMP traffic between the UPS and the Management Server. The thing that struck me right-away was the fact that I could see the a bunch of “SNMP Get-Request” but no “SNMP Get-Response” which means that Operations Manager did send an SNMP GET but there was no response. After a bit of intense staring i noticed what you see in the screenshot.

Installing Linux Integration Services v2.1 on Red Hat ES 5

Ok, so I got the task to install the Linux Integration Service for Hyper-V R2 on a RedHat Enterprise Server 5. Something that turned out to be a bit more to handle than I would have thought. So here’s a little How-To. Preparations Read the documentation provided in the Linux Integration Services download. Much of the information in this article is in there, but some parts are not. Otherwise I would not have bothered writing about it. 😉 I’m not going to go through the OS installation process here, but make sure to select the “Software Development” packages since you will be needing it. In case you missed it, you can install them later by running these commands. # yum groupinstall "Development Tools"# yum install kernel-headers I’m not actually sure that you need to run the kernel-headers install manually or if it’s included in the “Development Tools” package. The first gotcha i ran into was the fact that the link to the Linux Integration Services–previously known as Linux Integration Components or LinuxIC–on RedHat’s information pages gave me a 404 and a redirect to a bing-search that returned the exact same 404. The page have simply been removed by Microsoft without any form of redirection to the new page. Anyway, a search on http://download.microsoft.com for “Linux Integration Components” do return the new page, and that’s where I learned about the new name. Thank you for making it easy for us Microsoft! Here’s a direct link to the search on the current name. And here’s a direct link to the actual download page. This download contains an ISO file that you can mount using the Hyper-V- or VMM-console, or you can do as I did and download the ISO to the virtual machine, mount it locally, copy the files and unmount it. Like this. # mkdir /mnt/ISO# mount -o loop /root/LinuxIC v21.iso /mnt/ISO# mkdir /opt/linux_ic_v21_rtm# cp /mnt/ISO/* -R /opt/linux_ic_v21_rtm/# umount /mnt/ISO

Change Gateway Powershell Script

This script has pretty much already been covered in my previous post about Changing or Replacing an Operations Manager Gateway Server. This time I’ve basically put parameter support in it to make it e