(ZCM 2017 U1 appliance - upgraded today from 2017)

In the process of trying to get an accurate inventory I have been looking at the subdirs of /var/opt/novell/zenworks/collection/inventory. In the 'failure' subdir I have 45 files going back a week. Is it normal to have that many failures out of about 230 ws?

In the 'waiting' directory I have 39 files going back a week. The largest file is 294k. Is there a reason these are not being processed?

A number of the files in the 'waiting' dir have a series of ~1 at the end, for example:
1505306554-33a097b321d92140964adb8a5d3e9ea2-0-088-delta~1~1~1~1~1~1~1~1~1.xml

Why the ~1's at the end??

Can I delete old files (files older than today) in both of those subdirs or is that not necessary?

Thanks,
Dan