There is a setting on the server (Configure | Services | Inventory) where you can specify the number of days to keep a device in the database if it hasn't checked in. It's possible you have that configured and the machines that are disappearing are not sending Inventory scans, possibly they are outside the network and you aren't using a Gateway?
Roger is right about the causes of missing data, but you mention something about Banner IDs losing association? Can you be more specific on this? What is a 'Banner ID' and how do you experience this loss of association?
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I also have just noticed this inventory issue with data missing. If I manually start an inventory scan on the computer it populates inventory successfully. We have the stale computer setting set to 45 days and I have these computers on a report inside of this time and have definitely been online. Log files on the client are not showing anything to show an issue and cannot find an errorscan for the computers in question. We are using a gateway which is successfully sending inventory for all of our tests. All devices effected are laptops that regularly use VPN.
Thus far mixture of XP and Win7, LDMS 9.0 SP3 with inventory patched up to 126.96.36.199.
I don't have a lot more information other than this as yet as I have just started to investigate the issue today. Just thought I'd post with this information in case someone had some helpful information
What is your setting for Configure - Services - Inventory - Mange Duplicates: Devices on the Core Server?
If you have the setting for When MAC address matches turned on, this can create problems with laptops reporting over VPN, as the installed VPN adapter usually has a pre-programmed MAC address which is the same for all devices with the VPN software installed, so all devices checking in via VPN will check in using the same MAC address making LANDesk think they are duplicates. Best select the lowest setting: When MAC address AND device name match.
Thanks Frank, that does make perfect sense. Our settings are below. We changed to these settings as we were having problems with multiple devices when our POS devices were swapped out since they are rebuilt with the same device name. I'll guess we'll have to decide which is the lessor of two evils.
Hope this helps you too Jennifer. Sorry to seemingly hijack your post. How are you going with your issue?