OrbStack appears to report incorrect filesystem capacity and available space for certain APFS volumes mounted into containers.
Applications inside containers see incorrect free space values, while macOS reports the correct values.
This can potentially lead to applications incorrectly believing that the disk is full.
__Environment__
Hardware: Mac Mini M1
macOS: Sequoia 15.7.4 (Orbstack has full disk space access)
OrbStack: 2.2.1
Filesystem: APFS
Docker containers: qBittorrent, Overseerr
__Reproduction steps__
Create an external APFS volume with a total capacity of approximately 20 TB.
Mount the volume into a container:
volumes:
- /Volumes/Data:/data
Enter the container and run:
df -h /data
__Expected behavior__
The container should report approximately:
Filesystem Size Used Avail
mac 18T 2T 16T
matching the values reported by macOS.
__Actual behavior__
Inside the container:
Filesystem Size Used Avail
mac 2.2T 1.9T 348G
On macOS:
df -h /Volumes/Data
returns:
Filesystem Size Used Avail
/dev/diskXsY 18Ti 1.8Ti 16Ti
__Additional information__
APFS reports the following:
APFS Container Capacity Ceiling: 20.0 TB
Capacity In Use By Volumes: 2.0 TB
Capacity Not Allocated: 18.0 TB
It appears OrbStack may be exposing the "Capacity In Use By Volumes" value as the filesystem size instead of the APFS container capacity.
Other mounted volumes exhibit correct behavior, albeit with a lower capacity (6 TB and 4 TB).
The issue affects multiple applications suggesting it originates from the filesystem layer rather than individual applications.
Thanks for looking into this!
Edited for proper formatting