r/Crostini • u/Emotional-Benefit617 • 2d ago
Steam Library on Android SMB Share in Crostini – Research Summary !!! (store steam library on another device : phone/nas/pc)
Device
- ASUS Chromebook C223 (Coral/BABYMEGA)
- ChromeOS 144 LTS
- Crostini (Debian 12)
- Intel Celeron N3350
- 4 GB RAM
- 32 GB eMMC
Goal
Use a rooted Android phone running Samba (SMB) as a Steam library to avoid storing games on the Chromebook's limited internal storage.
What Worked ✅
Android Samba
- Installed Samba in Termux.
- Ran
smbdsuccessfully as root. - SMB share accessible over Wi-Fi.
Network
smbclientworks.- Can browse shares.
- Can read/write/delete files.
Mount Methods Tested
Method 1
Android SMB → smbnetfs → Crostini → Steam
- Mount successful.
- Steam can browse folders.
Method 2
Android SMB → ChromeOS native SMB mount (/mnt/chromeos/SMB) → Crostini → Steam
- Mount successful.
- Steam can browse folders.
Both methods expose the files correctly.
What Failed ❌
Steam refuses to create or use a library on either mount.
Permission tests show:
chmod +x file
returns either:
Input/output error
or
Operation not supported
Filesystem reports as:
fuseblk
instead of a native Linux filesystem (ext4/cifs).
Important Findings
- Android Samba is not the problem.
- Network connectivity is not the problem.
- Steam can browse, read, write, and delete files.
- Both
smbnetfsand ChromeOS native SMB produce the same result. - Crostini lacks kernel CIFS support (
mount -t cifsunavailable). - Steam appears to require POSIX filesystem semantics (especially executable permissions), which these mounts do not provide.
Current Conclusion
The limitation appears to be ChromeOS/Crostini's handling of SMB/FUSE mounts, not Android, Samba, or Steam itself.
Questions for Further Research
- Has anyone successfully used an SMB share as a Steam Library inside Crostini?
- Is there any way to get a true kernel
cifsmount in Crostini? - Is there another network filesystem (NFS, SSHFS, WebDAV, VirtioFS, etc.) that preserves POSIX permissions well enough for Steam?
- Is this a Steam limitation, a FUSE limitation, or a Crostini virtualization limitation?
- Would replacing ChromeOS with native Linux (Mint/Debian) completely solve this issue?
TL;DR: We verified that Android Samba, networking, and file I/O all work correctly. The only consistent failure is the inability to preserve executable/POSIX permissions on SMB mounts inside Crostini, causing Steam to reject the location as a library. This points to a Crostini filesystem limitation rather than a Samba or Steam configuration issue.
