Extremely long scan times for Serial Numbers

[zailleh]

Hi there,

I've identified a problem whereby it can take an extremely long time to scan in the SerialNumber of a device. This is accompanied by a large amount of data being send FROM lansweeper scan server to the target. For example, an 800 second scantime, the total data transferred to the target is approximately 20MB. I only noticed it because it flooded the link on one of our smaller sites when a couple of machines were scanned at once.

Has anyone seen this before/is this a known issue/is there a fix for this?

AssetID	CFGName		LastTime			ScanTime	Manufacturer
5594	SERIALNUMBER	2014-04-14 16:38:33.090		9902.32		Hewlett-Packard
5675	SERIALNUMBER	2014-06-24 12:51:23.013		8175.01		Hewlett-Packard
20298	SERIALNUMBER	2014-10-21 06:12:38.007		8172.26		Hewlett-Packard
5067	SERIALNUMBER	2014-09-24 12:12:43.973		8170.42		Hewlett-Packard
717	SERIALNUMBER	2014-10-09 19:00:12.817		7211.03		Hewlett-Packard
6540	SERIALNUMBER	2014-07-31 07:28:34.087		6235.98		Hewlett-Packard
635	SERIALNUMBER	2014-10-30 16:46:35.183		3372.92		Hewlett-Packard
3535	SERIALNUMBER	2014-04-09 12:43:23.460		2963.79		Dell Inc.
7987	SERIALNUMBER	2014-10-31 11:04:40.923		2479.10		VMware, Inc.
29462	SERIALNUMBER	2014-10-31 11:01:22.400		2388.62		VMware, Inc.
8610	SERIALNUMBER	2014-10-31 11:01:27.977		2380.09		VMware, Inc.
29463	SERIALNUMBER	2014-10-31 10:59:19.243		2263.50		VMware, Inc.
6903	SERIALNUMBER	2014-05-23 11:09:15.830		1946.65		Supermicro
29464	SERIALNUMBER	2014-10-31 10:49:28.947		1670.28		VMware, Inc.
9083	SERIALNUMBER	2014-10-31 12:53:58.893		1487.28		Hewlett-Packard
9670	SERIALNUMBER	2014-10-31 12:48:40.290		1159.93		VMware, Inc.
9847	SERIALNUMBER	2014-10-31 12:49:14.680		1133.22		VMware, Inc.
8628	SERIALNUMBER	2014-10-31 12:48:09.483		1119.48		VMware, Inc.
8636	SERIALNUMBER	2014-10-31 12:46:45.153		1088.59		VMware, Inc.
20219	SERIALNUMBER	2014-09-12 09:20:35.457		1076.43		Hewlett-Packard
9348	SERIALNUMBER	2014-10-31 12:48:59.850		1074.83		Hewlett-Packard

[Hemoco]

Software and Serial Number are the only wmi queries that query the windows registry.
The overhead in WMI traffic is much larger than the actual data returned from the queries.

[zailleh]

Thanks for that, good to know.

Is there any reason why it would be specifically for the Serial Number and not the other WMI queries?

On a rescan of one of the computers afflicted with this, it took 821 seconds to get the Serial Number and most other things were around 1-2 seconds to scan, aside from software (160) and Quickfix (60).

By comparison, it takes an average of 2.5 seconds to get the SerialNumber using PowerShell.

Get-WMIObject -Class Win32_Bios -Computername $computername | Select SerialNumber

[Hemoco · Accepted solution]

This happens when there is a really bad network connection between the lansweeper server and the scanned computer.
WMI is constantly retransmitting IP packages to keep up the connection.