itimpi

No - you DO get all Unraid features (including VMs and Docker) and keep your lifetime update status.   All releases of Unraid are functionally equal, and the web site should make this clearer.

Looking through the diagnostics it seems the parity1 drive has gone offline and as a result there is no SMART information for it.   You might want to check the power/cabling to the drive.

The User Scripts plugin can be used to initiate the scripts on a selected schedule for devices permanently available.   Alternatively the Unassigned Devices plugin allows you trigger a script when a particular drive is plugged in.
 
The content of the script will depend on exactly you want to copy and to where.

Those look fine from a scheduling perspective.   
 
We do normal, however, recommend that the automatic scheduled checks are set to be non-correcting so that if you have a drive playing up it does not end up corrupting parity before you realise there might be an issue.   Then it is only the manual checks that are set as correcting after you have fixed any hardware related issues that might have caused parity to be partly invalid in the first place.
 
  
 
You can get to the flash drive by clicking on the Boot device on the Main tab.     If you want it to be visible over the network (by default it is not) then you need to set the SMB settings to allow this (in which case if shows up as the 'flash' share.
 

The end of both logs finishes with errors along the lines of:
Apr 22 08:33:48 Tower kernel: ata14.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 Apr 22 08:33:48 Tower kernel: ata14.00: irq_stat 0x40000001 Apr 22 08:33:48 Tower kernel: ata14.00: cmd a0/01:00:00:00:01/00:00:00:00:00/a0 tag 7 dma 16640 in Apr 22 08:33:48 Tower kernel: opcode=0x12 12 01 80 00 ff 00res 00/00:00:00:00:00/00:00:00:00:00/00 Emask 0x3 (HSM violation) Apr 22 08:33:48 Tower kernel: ata14: hard resetting link Normally we would think these were power/sata cabling related but the fact it has occurred at the same point twice suggest it may really be a drive problem if ata14 is the new drive.

You can use the procedure documented here in the online documentation accessible via the ‘Manual’ link at the bottom of the GUI or the DOCS link at the top of each forum page. The Unraid OS->Manual section in particular covers most features of the current Unraid release.

That is a clean looking check with no errors reported so I would expect all data to reappear after running the repair.

This would have also formatted the emulated drive thus wiping its data.    You would have needed to run the procedure for fixing disk1 to make it mountable before attempting any format.

You need to run without -n and adding -L

No, it is always based on the number of folders in the files path.

You have the Minimum Free Space setting for the 'domains' share at 195GB and none of your drives have that much free space.

Rebuilding a drive will not clear an unmountable status.    The procedure for this is covered here in the online documentation accessible via the ‘Manual’ link at the bottom of the GUI or the DOCS link at the top of each forum page. 

You can do a manual upgrade to the current 6.12.10 release by following the procedure documented here in the online documentation accessible via the Manual link at the bottom of the Unraid GUI.  In addition every forum page has a DOCS link at the top and a Documentation link at the bottom.   The Unraid OS->Manual section covers most aspects of the current Unraid release.
 
Having done that the purchase option should now work.    If you still encounter problems you will need to contact support as they handle all licencing issues.

I would certainly recommend removing stopping the array as with disk4 playing up it will take forever 😞
 
It is your choice as to whether you want to try and resolve why disk4 is having issues or initially just get disk3 up and running?  It is possible that disk4 just has a cabling issue (power or SATA) and the drive is physically OK.

You should post your system's diagnostics zip file in your next post in this thread to get more informed feedback.  It is always a good idea to post this if your question might involve us seeing how you have things set up or to look at recent logs.

I would say that it is definitely your flash drive as the messages mention [sda] which is standard for the flash drive.
 
I do not think it will help in this case, but the key point of Safe Mode is that it stops plugins from being loaded (plugins can change system components) and that applies regardless of whether you are in GUI mode or not. 

Do you know which drives(s) are parity drives?   You will only lose data if you accidentally assign a data drive as a parity drive.   If you are not sure then follow the procedure documented here in the online documentation accessible via the Manual link at the bottom of the Unraid GUI.  In addition every forum page has a DOCS link at the top and a Documentation link at the bottom. 
 
Having said that you say the backups are on an unassigned drive?    Even with nothing assigned to the array I think you can still download the Unassigned Devices plugin and then mount such a drive to get at your backups.
 

No.   The disks will be Cleared so that parity is unaffected.

A gigabit LAN silently downgrading to 100Mbps normally means that there is at least one twisted pair not making connection in the cable between the router and the server.   This can be either a broken wire within the cable or a pin not making contact at either end.  I would suggest trying different cables and/or ports.

You can always use the Custom TAB to add anything as long as you have a URL for it.   I personally use it to add a DOCS tab there.

Did you copy across the contents of the 'config' folder from the old flash?    That should have gotten the plugins and docker templates back just as they were.

It is definitely possible to move the data.   
 
However are you sure the drive has failed?   More often then not a drive is disabled (because a write failed) due to an external factor such as cabling or power.  You should post your system's diagnostics zip file in your next post in this thread to get more informed feedback.   You can also try running an extended SMART test on the drive as if it passes that the drive is probably OK.

You can use the New Config tool to reset the array as described here in the online documentation accessible via the ‘Manual’ link at the bottom of the GUI or the DOCS link at the top of each forum page.   I recommend that you start by using the options to keep all current assignments to reduce the chance of error and then return to the Main tab to remove the drive before starting the array.   Since you have removed a drive parity will need to be built sgain.

You need to set either the “mirror to flash” option or set the “remote syslog server” to be your Unraid server to get anything recorded as mentioned in the syslog server link.   The settings you have just set it up in ‘listen’ mode

In theory reallocated sectors are not a problem as long as the number remains stable, but they are never a good sign, and if they continue to increase the drive will need replacing.   Definitely want to keep an eye on it.    Might want to consider running the extended SMART test on the drive as that is a good way to test it’s health.
 
if you click on the orange icon for the drive on the Dashboard and select the Acknowledge option Unraid will only notify you again if it increases.