Hello everyone! You can limit share size through the unraid GUI by changing the shares export to use "Time Machine" in Unraid. It doesn't matter that time machine is for mac, the limit still applies to SMB and Windows.
***HUGE DISCLAIMER***
This requires "Enhanced macOS interoperability" to be enabled which, has an annoying downfall of occasionally preventing file changes in windows. (Example: On your windows client, you update and save a word document. After saving, for the next ~5 minutes, you cant rename or delete it). See this unraid post for more info on that issue. Personally, I stopped using this setting specifically due to this issue, but simply waiting, or logging off/on will solve the problem.
If you don't care about the listed downfall, here are the steps to use Time Machine to limit share sizes:
1) Navigate to 'Settings > SMB'
2) Look for "Enhanced macOS interoperability" verify that the setting is 'Yes'. If the setting is no, you must stop the array, then come back here to change it.
3) Next, Navigate to 'Shares > [share name]'
4) Under "SMB Security Settings", Find the drop down for 'Export' and change it to "Yes/Time Machine"
5) Enter your size in MB (1000000 Megabytes = 1 Terabyte)
6) Apply
Below are some pics for reference:
Enhanced macOS interoperability
SMB Share settings and windows results BEFORE the change
SMB Share settings and windows results AFTER the change
Side notes
-The number isn't exactly 1000 GB thanks to windows usual formatting shenanigans.
-The above steps work for Unraid v6.12 ... unknown if they will work for other versions.
-Check out some of the alternate suggestions below if you don't want to deal with the "Time Machine" disclaimer.
Alternate suggestions/solutions
-In the above example, I am using a ZFS pool and am very limited in options. If you are using a multi-disk array for storage, consider using "Included/Excluded" disks instead, and just limit the share to a single disk.
-If you are competent in the terminal, a user script would be an excellent alternative to this. A script which limits the directory size should work (Note, this requires creating mount points, setting permissions, etc. all while unraid is running... you REALLY need to be good in the terminal to do this). A script which removes files older than X days from directory could also work.
-As of Samba version 4.17 ... It includes storage quotas "smbcquotas". Unraid 6.12 currently uses samba version 4.17.12 (you can check your samba version by putting 'smbstatus' into the terminal). If you feel like messing around, here is documentation directly from Samba about configuring this feature: "Samba quotas" . It is likely that this feature will eventually get implemented into unraid if you are patient.
This is my first post so I greatly apologize to the moderators for any mistakes I made. Thank you for your patience, good luck everyone!
