[Help] Time Machine does not detect SMB share when a quota is applied (TOS-6, F4-424)
Posted: 25 Nov 2025, 16:33
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.
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.