I thought this was going to be a genius idea, but I have quickly found it may not even work - unless the power of collective (Synoforum) knowledge can help me achieve my goal. 
Setup
NAS1 (Master): RS812+ with 4x 2TB SHR providing 6TB storage
NAS2 (Local backup only): DS718+ with 1x6TB - no redundancy (yet), + 1x1TB with USB WD USB drive as slow backup as required
Full backup of master NAS1 (only) in cloud
HP Procurve 24port switch with each NAS dual network ports bonded
My plan was to:
Remove all 4x2TB drives and temporarily replace with a new 8TB HDD in NAS1 (RS812+)
Restore the rsync backups from NAS2 (DS718+) to the new 8TB drive (partially - sidebar: I'm confident in the data, but I have been having permission control issues with rsync)
Restore Hyperbackup from cloud (partial or full recovery, depending on speed)
Once fully restored, or at least confident in the integrity of backups for recoverability - then return 4x2TB drives still intact and unchanged.
Then use 6TB and 8TB drives in NAS2 either as 14TB of non redundant storage or possibly as 6TB SHR
My plan has quickly come unstuck as I have realised I cannot bring the new drive up.
Newfound Assumptions:
Status (some obvious)
NAS1 Status light green blinking.
No IP showing on my router (I've always had a fixed IP, for NAS1 and NAS2, but the router doesn't show NAS1 now, and I can't connect with a browser to previously assigned IP)
Router still has address reservation and MAC in place, but only NAS1 appears in the device list.
DSAssist only finds NAS2 (on Mac constantly crashes, on Win10 doesn't even find NAS2).
find.synology.com only finds NAS2, diskstation:5000 doesn't respond, quickconnect.to can't find NAS1 anymore.
The only option I can see now is to put the 8TB drive into NAS2 (as drive 2) and apply no redundancy.
I could test the Hyper backup cloud data, but doesn't prove much with the rsync backups sitting on NAS2 6TB disk1.
Is there a way to carry out my original plan to validate my backups and recovery procedure? (rsync local, and Hyperbackup cloud)
Is there a relatively easy way to validate a "from scratch" recovery procedure?
Setup
NAS1 (Master): RS812+ with 4x 2TB SHR providing 6TB storage
NAS2 (Local backup only): DS718+ with 1x6TB - no redundancy (yet), + 1x1TB with USB WD USB drive as slow backup as required
Full backup of master NAS1 (only) in cloud
HP Procurve 24port switch with each NAS dual network ports bonded
My plan was to:
Remove all 4x2TB drives and temporarily replace with a new 8TB HDD in NAS1 (RS812+)
Restore the rsync backups from NAS2 (DS718+) to the new 8TB drive (partially - sidebar: I'm confident in the data, but I have been having permission control issues with rsync)
Restore Hyperbackup from cloud (partial or full recovery, depending on speed)
Once fully restored, or at least confident in the integrity of backups for recoverability - then return 4x2TB drives still intact and unchanged.
Then use 6TB and 8TB drives in NAS2 either as 14TB of non redundant storage or possibly as 6TB SHR
My plan has quickly come unstuck as I have realised I cannot bring the new drive up.
Newfound Assumptions:
- It appears as not possible to boot onto the new 8TB drive without hard resetting NAS1.
- If I do reset NAS1, it will be a nightmare to recover the original 4x2TB unchanged master drives (not impossible, but beyond my knowledge/capability).
Status (some obvious)
NAS1 Status light green blinking.
No IP showing on my router (I've always had a fixed IP, for NAS1 and NAS2, but the router doesn't show NAS1 now, and I can't connect with a browser to previously assigned IP)
Router still has address reservation and MAC in place, but only NAS1 appears in the device list.
DSAssist only finds NAS2 (on Mac constantly crashes, on Win10 doesn't even find NAS2).
find.synology.com only finds NAS2, diskstation:5000 doesn't respond, quickconnect.to can't find NAS1 anymore.
The only option I can see now is to put the 8TB drive into NAS2 (as drive 2) and apply no redundancy.
I could test the Hyper backup cloud data, but doesn't prove much with the rsync backups sitting on NAS2 6TB disk1.
Is there a way to carry out my original plan to validate my backups and recovery procedure? (rsync local, and Hyperbackup cloud)
Is there a relatively easy way to validate a "from scratch" recovery procedure?
