[Help] Time Machine does not detect SMB share when a quota is applied (TOS-6, F4-424)

[Goshary]

Hello TerraMaster Support,

Maybe this issue has already been discussed somewhere, but I could not find any information about it through search. Please let me know if this is a known limitation or if I am missing something in the configuration.

I am using a brand new TerraMaster F4-424 with the latest TOS version available as of today and iMac with Sequoia 15.x latest.

I have a reproducible issue related to Time Machine + SMB share quotas:
• If I create a shared folder, enable Time Machine for it, and do not set a quota, macOS detects the share and backups work normally.
• If I set any quota on that same share, macOS Finder still mounts it correctly via SMB, but Time Machine cannot see it at all in the list of available backup destinations.
• Removing the quota immediately makes the share visible again to Time Machine.

This happens even on a completely new, empty share with clean permissions.

As an additional note: when I initially set up the NAS about a month ago, Time Machine only worked reliably on the default Public share where no quote can be applied (...) . Custom shares were visible but refused to start backups. That issue eventually stopped appearing, and custom shares now work — but only as long as no quota is applied.

My goal is to use Time Machine on a dedicated share with a fixed quota, without relying on a SparseBundle ugly workaround.

Could you please tell me:
1. Are quota-limited Time Machine shares supported in TOS-6?
2. Is this a known issue with SMB fruit integration or quota handling?
3. Is there any recommended workaround?
4. If this is a bug, will it be fixed in TOS 7 ?

Thank you very much in advance. I can provide logs or run additional tests if needed.

[CursaYang]

Hello, in TOS 6, we designed a separate storage quota for Time Machine, which would conflict with the storage quota of shared folders.

If you need to limit the amount of NAS space occupied by Time Machine backups, you can set a storage quota in the authorized directory of the Time Machine backup.

In the new TOS 7, we have removed the storage quota setting for Time Machine and unified it to use the storage quota of shared folders.

[NadiaEira]

To control the amount of NAS space used by Time Machine backups, you can establish a storage limit within the authorized directory of the Time Machine backup.