Dell EMC uses Secure Remote Services (SRS, formerly known as ESRS) to enhance the tech support experience for their products. There’s two sides to this support: connect home, and connect in. Connect home is your device itself dialing back home to Dell EMC to report various things such as errors, automatic support uploads, etc. If either of this results in a Service Request at Dell EMC, a engineer can then use SRS to dial in / connect in and have a look at the faulty system. The latter saves you from having to host a Webex session.
Dell EMC likes to have all Dell EMC systems connected to SRS, again for two reasons. First of all, it reduces the time spent by engineers in troubleshooting an issue. If an engineer can dial in himself, without having to negotiate a Webex session with the customer, that means more SRs per engineer per day and lower support costs for Dell EMC. Secondly, it will result in faster incident resolution, and thus a happier customer. The support engineer can look up the state of a defective drive independently, and order new parts while the customer is sleeping. Win-win!
I recently installed a new Data Domain DD6300. Part of the whole installation procedure is to run a DD OS upgrade to bring the system up to the target DD OS release. You can find the target releases over 
Several of our Data Domains are end-of-life and need to be replaced with new hardware. In most of the cases it’s a small site with a small Data Domain that only holds roughly 1 month of backups. In these cases we just install a new Data Domain next to it, reconfigure our our backup software, and that’s it. After a month, the old backups have expired and you can switch off the old Data Domain.
I recently deployed a new 32TB Data Domain DD3300 system. The initial configuration is easy and familiar enough. Connect to the system via the serial cable, setup iDRAC, and run the initial configuration wizard. Afterwards the rest of the configuration can be performed via SSH and/or the GUI.
Increasing the storage capacity of a Data Domain is usually a matter of adding an additional disk shelf to the Data Domain head. Upon connecting the additional enclosure your new disks will be in an Unknown state. This does not necessarily mean there’s anything wrong with the topology of the system, but just indicates the disks aren’t in use just yet. This is however easily fixed with a couple of CLI commands.