Questions: Setting Up a Basic Time Machine SMB Share

I have some questions about the documentation page mentioned in the title. I have enough uncertainty about what I’m reading there that it has kept me from setting up my backups altogether—which is not good! I hope to get some clarity here. Sorry in advance for the wall of text, but maybe all the detail will help improve the page.

  • What is “basic” about what we’re doing here? Calling it basic implies that I might want to do something else, and even that there might be a “non-basic” page with suggestions, but considering that Time Machine is largely undocumented, fiddling with the setup seems risky, and I can find no such page. Also, some of the information mentioned below seems decidedly non-basic. I realize this might sound like I’m just picking at words, but questions like this makes me wonder if I know what I’m doing when I follow the instructions.

  • I’m already stymied at Step 1: “Create the user(s) for this SMB share. Go to Credentials > Local User and click Add.” There’s no top-level “Credentials” item. Okay, I see this page is for Scale and not Core, which I am running. Yup; it looks like Scale uses “Credentials” instead of “Accounts”. Should I upgrade to Scale if I want to serve Time Machine, given that there are no similar instructions for Core?

  • Huh, the link for “Create the share and dataset” doesn’t work. Okay, typo: it seems to have been intended to point at #creating-the-share-and-dataset.

  • It mentions “When accessing from a Windows client, having more than 512 snapshots on the TrueNAS box can lead to performance issues.”

    • Is this really a problem with the total number of snapshots on the TrueNAS box or only with the number of snapshots of datasets mounted on Windows machines?
    • Why would a windows machine be likely to mount a dedicated Time Machine share, given that the .sparsebundle files written there can only really be read by a Mac?
    • How is this information relevant to Time Machine setup? Isn’t it a more general issue?
    • It says, “Windows client often attempts to load all snapshots into the ‘Previous Versions’ tab.” It’s really unclear how a Windows client would ever see a ZFS snapshot, much less identify it as a previous version of anything. Are we talking about some kind of client program for controlling the whole TrueNAS box?
  • Minor issues with: “You can either create the dataset to use for the share on the Add Dataset screen and the share, or create the dataset when you add the share on the Add SMB screen. If you want to customize the dataset, use the Add Dataset screen.”

    • The words “and the share” don’t parse for me. I’m inclined to assume that they are just detritus from a previous edit, but I’m unsure, so again I wonder if I really know what I’m doing.
    • It took me more time than it should have to realize that I want to use the first option, because I might care about some advanced settings… but it made me wonder why the instructions even mention the second option. We’re creating a new dataset in both cases, I have to the visit the “Add DataSet” screen anyway, and having more options just seems to complicate an already complicated picture
    • …ah, but it seems rhese aren’t really alternatives? once I created the dataset, I still needed to “Add SMB” in order to enable sharing. And I don’t see any option in that screen for adding a new dataset; I have to give it a path to share.
  • Why am I directed to “Select the Dataset Preset option [I] want to use?” My understanding is that SMB is the recommended protocol for TIme Machine shares (and after all it’s in the title of the page), and if anything I should be told explicitly to choose that one. In fact, it looks like I should really ignore everything from here until at least the paragraph that begins “If you want to configure advanced setting options,” where the Sync option could possibly be relevant. Am I missing something here?

  • Is there a specific recommended Sync setting for Time Machine use? Would “always” slow my backups down?

  • Also it seems I should ignore the paragraph about case sensitivity and allow the default to take effect.

  • Arriving at the “Add SMB” screen, which I need to use after all, the purpose option I see is not “Basic time machine share” (as in the docs) but “Multi-user time machine.” No clue whether that is a Scale/Core difference or a document-o.

  • I see nothing in here about setting a quota for the filesystem, which would seem to be an essential part of setting up Time Machine, so it doesn’t fill the pool.

Thanks for reading, and for answering.