Recommended Approach for upgrading drive

And two cautions:  Its best to use different share names when copying to an intermediate drive.  Dupklicxate share names can confuse the NAS.  Also, if you are using SSH and cp to copy, DO NOT simply "cp" a share.  Shares are BTRFS sub-volumes.  You must create the share via the GUI before you copy the contents.

I was afraid of that.  I will just restore from the backup NAS, that is way more straight forward.  

When I pull a drive out (in order to create a new volume of the same name), do I need to do anything else before or after pulling it to actually remove the volume completely, in order to create a new volume of the same name?  Or just pull it and its gone?  Does it need to be "deleted" in some way through front view or otherwise?

The reason I arranged things the way I did with an SSD for the OS was not for speed per say, it just happened to be a drive I had laying around.  That is indeed the drive with the OS.  the main reason I did it like that is so that the OS drive is completely separated from my data volumes, I can change my various data volumes at will without affecting my OS installation.  So I don't think I should have to move any apps or do anything other then setup the new volumes and restore to them.  worst case if the OS drive fails, I'll deal with it, not the end of the world, but again it will be separated from my data volumes.

I realize my configuration is non standard.  I am trying to avoid raid5 more than anything.  Its possible I will mirror one of the volumes later.  Anyway this is how I chose to do it this time.  Perhaps it would be ok in the future to have two mirrored volumes, in which case the OS would be on one of those mirrored arrays and the other array would be only a data volume, something like that.  But I more or less just decided I don't want to deal with even mirroring and I'm relying on my NAS backup and offsite backup for now.  

also for clarity, I am not using X-Raid, using flex-raid...  All volumes were created as JBOD.  

I have already DESTROYED the other two volumes in preparation to restore to new devices.  

However now getting a weird error, I have rebooted it several times to flush everything out, but now when I try to use front view it is prompting me  dozens of times and forever for admin login and password, its not remembering it for any length of time, I have tried several different web browsers same result.  Any idea what might be suddenly causing that?

I'm wondering if something in the OS was using some space on one of the other volumes I have DESTROY'd.  Not sure why it would be, but that's the only thing I changed, destroyed both volumes, there is only one drive in the readynas now, the OS drive...and  it SHOULD be functioning fine...but its becoming unwieldy to have to re-enter the admin login and password over and over again.

Also when I tried to then insert one of the new drives and add a flex-raid JBOD volume, its coming back with an error about can't find device or something like that.

So...  somehow destroying the two non-OS JBOD volumes seems to have broken my OS functionality.

also since DESTROYING those two non-OS JBOD volumes, now suddenly I see from command line that my / partition is reporting 0 free...  which doens't make sense, but that must be why I'm generally having problems, so I'll try to track that down.