Hello,
Hopefully by now you've had a chance to upgrade your systems to NimbleOS 2.1 since it's official GA in July/August, and taken a look at the redesigned VMware Plugin for the Legacy Client (also referred to as the C Client).
Whilst overall the feedback for the new plugin was overwhelmingly positive since it's release, the main source of criticism came via the appending of four zeros to any Nimble volume created via the plugin wizard - which was done to ensure there would be no naming convention clashes with other volumes on the array - so a volume called ESXDatastore would be called "ESXDatastore0000" on the array. The plugin also created it's own iSCSI Initiator Group called ESXHosts, again with four zeros appended to it.
I'm pleased to report with the release of NimbleOS 2.1.7.0 last week we have upgraded the plugin so that any Nimble volumes created are the exact naming convention requested by the user of the plugin - ie no "0000" appended to the end of the name 
The plugin still creates it's own Initator Group called ESXHosts, but does not append the zeros to it either.
All systems running 2.1.x should automatically be able to download 2.1.7.0 as well as all 2.0 and 1.x systems, however to confirm that your system is not blacklisted due to a known condition, check out Infosight and click the firmware version of your array. Also note any upgrade from 1.x and 2.0 to 2.1 will require an update for any host side MPIO tools such as our VMware or Windows Nimble Connection Manager tools.
