Resilio error on Android phone: No enough space on device

[zrzhu111]

Reailio was set up as "Selective sync" on my phone. When I tried to sync a folder (25gb) on my phone with a folder (90gb) on QNAP Nas. It keeps giving me error No enough space on device. How can I fix the error?

I don't need to download all 90 gb data to my phone since my phone only has about 1gb free space. Since it's selective sync, I thought the full file will not be downloaded to my phone, only placeholder files of 75gb (90-25) will be created on my phone, and these placeholder does not use much space.