Of course you can know both 
The difference between the two is where your media (movies,tv, and music) is located between NAS’s. If the locations (share names) are the same on both, it will not matter at all. As example, I use /volume1/movies, /volume1/tv, and /volume1/music (very simple).
Here is where the procedure changes depending on what you do.
-
If you perform a “Synology migration”, where you move all the disks from the old NAS to the new NAS and reinstall DSM, all your media will still be there and intact with the same names it had before. The Synology migration process only re-installs DSM. It does not erase the entire volume. All you need to do is reinstall PMS in Package Center. Your PMS Library will be intact because Plex keeps the software and your Library in different locations (
/volume1/@appstoreversus/volume1/Plex/Library). -
If you are moving to a new NAS, and your media isn’t in shares with the same names we have to adjust for this. Your Library will still be in Plex share but it will be looking for your media in different share names.
Here is the full procedure to copy from one to another. Since this does make a mirror copy, you’ll have to do minor editing of settings (Server name, etc) in addition to correcting the media locations (which I detail below).
-
Open PMS.
-
Go to Settings - Server - Library. Uncheck EVERYTHING and save the changes. This puts PMS in fully manual library mode.
-
Enable SSH on your existing Synology and ssh to it. log in as ‘admin’ with the admin password.
-
Be certain to stop PMS in Package Center
sudo -su root cd /volume1/Plex tar cf SynoLibrary.tar ./Library chown your_username:users SynoLibrary.tar -
When this step is done
SynoLibrary.tarcontains the entire Library and all information. It also is the perfect backup of your PMS Library and all configuration information. -
Take this file (SynoLibrary.tar) to the new NAS. Now reverse the process with a minor deviation.
-
Install PMS and let it start once
-
Wait 1 minute (until NAS quiets down) and then stop PMS.
-
Copy the file
SynoLibrary.tarinto the new Plex share -
SSH into the new NAS
sudo -su root
cd /volume1/Plex
mv Library Library.unused
tar xf SynoLibrary.tar
chown -R Plex:users ./Library -
Start PMS and open it in your browser as always
-
For each Library section you have defined,
12a ‘Edit Library - Add Folders’
12b. Add the new location where your media is now. Do not delete the old location yet.
12c. Save the change
12d. Update that single Library only (upper right corner ‘Update’)
12e. PMS might start tagging all your media with a ‘2’ indicating it thinks you have two copies. This is normal because there now are two locations in the database. -
With all libraries edited and updated:
13a. Settings - Server - Library: Re-enable all the settings you had before, just the way you had them and Save,
13b. Edit each library one last time, removing the old folder locations. -
Now we’ll clean up. Left Panel: Update Libraries and let all libraries update. Empty Trash when it’s complete. Clean Bundles.
-
When the NAS is quiet again (may take a while) “Optimize database”
That’s it. Go check your connectivity and make any other changes you wish with the new NAS.
Edit: major typo up top.