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Posts Tagged ‘ProcMon’

Nested VM Performance is Slow

August 27, 2017 Leave a comment

This is taking forever!

That’s what I was thinking when deploying nested virtual machines on vSphere 6.5 in my lab (OK, it’s my laptop). The configuration was simple enough; the latest version of VMware Workstation, an ESXi host VM, & a Windows Server 2012 R2 VM nested in ESXi. Simple enough, right?

Watching the console of the nested VM I notice it seemed…slow. When the VMware logo on the POST screen finally appeared I could see the screen painting making it look like an 80’s arcade game.

As you can see that took way too long. So with Process Monitor running on the laptop I power on the VM again. After it runs for about a minute the fun task of sifting through the ProcMon log begins. If you’ve ever used ProcMon you know it’s more of an art than a science. The first thing I always do is use the analysis tools from the menu.

Honestly, I just go through each of them & see if something jumps out at me. Real technical, I know. In all the sifting & sorting one thing that kept jumping out was the Anti-Virus software.

This wouldn’t be the first time an Anti-Virus product interfered with an application working properly so I started digging through the AV interface. After clicking around for a bit I come across some very interesting settings.

“Enable hardware-assisted virtualization” & “Use nested virtualization where available”. Those look promising. I uncheck both of those settings & give the laptop a reboot. This time when the nested VM boots it POPS!

According to Avast’s website, the software is supposed to detect that virtualization applications like VMware Workstation or Microsoft Hyper-V are installed & automatically disable these settings.

Cheers!

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Backlog: ODBC Connection Failed

March 17, 2017 Leave a comment

So you’ve got a Microsoft Access database with linked tables to a SQL server that looks something like this.

When opening one of the linked table you get an error that says, “ODBC–connection to ‘DP’ failed”.

When you click OK you get a message that says, “Microsoft Access can’t open the table in Datasheet view”.

Hmm, what up with the ODBC connection called “DP”? What say you Procmon?

Result = NAME NOT FOUND. Oh, the ODBC connection doesn’t exist. Create the ODBC connection & you are good to go.

I admit that you could have also just gone & looked at the ODBC connections in the Control Panel to figure out it doesn’t exist but it was really just an excuse to use Procmon.

Printer Keeps Going Offline

September 19, 2014 1 comment

A user reported that they had printed some documents but that they were not printing. Looking at the print server I saw that the printer was showing as Offline.

1 Offline

I was able to ping it as well as bring up the web interface. As a test I disabled SNMP checking for the printer’s port by doing the following:

  • Right click the printer & select Properties.
  • Select the Ports tab.
  • Select the printer’s port & click Configure Port.
  • Uncheck SNMP Status Enabled.
  • Click OK.

The moment I did that the printer went to a Ready status & the documents printed. I have two printer server that both have this printer configured. They were both experiencing the issue so I believe the issue to be with the print servers.

OK, perhaps the SNMP string got changed on the device. I ran an SNMP test (Paessler has a good free one http://www.paessler.com/tools/snmptester) but it check out good using the SNMP string configured on the printer’s port.

So when in doubt use ProcMon. First, I set the printer’s port back to using SNMP checking then fired off ProcMon on the printer server. Within a minute the printer switched from Ready to Offline. I stopped ProcMon & begun the artful task of sifting through the capture. I noticed a section where the print server starting sending SNMP requests to all the printers. I saw a response for all the other printers but none for the one in question. Note below all I saw were UDP Send.

2 no snmp response

So for some reason the printer is not responding (or not responding timely. I didn’t feel like doing a full on packet capture). So like everything else if it’s not working, reboot. Once the printer came back up it I started another ProcMon capture. This time I saw the SNMP requests & responses (UDP Send & UDP Receive).

3 with snmp responses

Sure I could have just left SNMP unchecked on the printer port but that wouldn’t have really resolved the issue; just masked it. Now if it continues to happen I may have to see if there is a newer firmware for the printer that resolves SNMP issues (or contact HP, ugh), but for now a printer reboot will do the trick. I also got to see a little more under-the-hood thanks to ProcMon.

Categories: Computers Tags: , ,
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