When I used Qsync Client to back up to an external HDD connected via USB from my PC to my QNAP (TS-431P), I encountered an error partway through and the backup failed. After that, the free space on the TS-431P system volume dropped drastically, and now there is 0% free space left. The volume type is a static volume. What’s odd is that the total capacity was originally 7.17TB, and that’s what is shown under “Storage & Snapshots” for volume usage, but in Control Panel under “Shared Folders,” it shows the size of that drive as 5.22TB. Is the system area unnecessarily consuming space? I’m really stuck at this point. Please give me some advice.