I Have a readnas 4220 configured with on volume, the size of the volume is 14.53 TB and the free space on that volume is 77.95 MB, There is no snapshot.
We need more information here. How much is stored on the volume for instance, so we can understand the discrepancy. Perhaps post a screenshot of the volume page and the shares page.
It'd also be helpful to know what firmware the NAS is running.
The snapshot protection was enabled and suddnly the the protection went to off and the old snapshots was deleted automatically but the space that snapshots was accupied didnt unallocate.
You are running 6.1.0 which is incredibly old firmware. I believe that's the firmware the RN4220 first shipped with from the factory back in 2013.
We've introduced better default settings for new LUNs and improvements for file/snapshot deletion amongst many other changes since then.
The NAS is showing the space as both fully allocated and in use. Most likely your LUN has filled your data volume.
Note that with LUNs it's not how much data that's on the LUN that matters but it's capacity for space it uses. Using CoW and snapshots will increase the space used.
Can you still access the data on your LUN? If so I would refrain from writing to it and backup all your data from the NAS and verify that your backup is good.
Once you've done this I would suggest that you then update the firmware to the latest. Once you've done that please do a factory default (wipes all data, settings, everything) and restore your data from backup.
Caveat: In case you get a chance to update, do not directly update to the most recent fw release (6.6.1), but follow the recommended sequence of update steps in the release notes of the corresponding fw.
Friendly suggestion: Finally do not upgrade to 6.6.1, but stop upgrading after 6.6 and wait for 6.7 to be released.
The number of reported issues about 6.6.1 is legion in the meantime. You might want to spend some time to research on this portal.
6.6.1 is a stable firmware release, but if you'd rather use 6.6.0 or 6.5.2 that's up to you, but you certainly should run much newer firmware than 6.1.0.
6.6.1 is a stable firmware release, but if you'd rather use 6.6.0 or 6.5.2 that's up to you, but you certainly should run much newer firmware than 6.1.0.
I agree.
Personally I use 6.6.1 with AntiVirus off (though I am trying 6.7.0 beta on my backup NAS, and likely will install on the main NAS soon).
Balancing has been greatly improved since the 6.1.0 release you were running, but upgrading the firmware with a full volume is not without its risks, so that's why I made the conservative recommendation to go down the backup, update, verify update successful and factory default (wipes all data, settings, everything) route.
