The disk is full
Running out of space inside Linux, or on your Mac.
There are two different "full"s, and the Storage card on the Overview tab shows both.
Full inside Linux#
"No space left on device" inside Linux, or the usage bar is orange.
- Make room inside: run Clear caches inside Linux from the Maintenance card, and delete what you don't need.
- Raise the limit: drag the Storage card's slider up. The disk grows and Linux's filesystem is stretched to match at the next start.
- Let it grow by itself: with a dynamic disk, Grow automatically when it runs low adds 8 GB at a start whenever it's 85% full, up to the limit.
Full on your Mac#
A dynamic disk only takes the space it has written, but that grows as Linux writes — and it never shrinks back, even after deleting files inside Linux. The Storage card shows what it really takes ("Actually used on your Mac"), and its footnote shows your Mac's free space.
See Reclaiming disk space for what can be deleted.