Mac Mini Time Machine Server

macprobuffalo

macrumors member
Original poster
Feb 27, 2015
50
7
Hello,

I am setting up a 2018 Mac mini for a family member. We are attaching a OWC external HDD enclosure for Time Machine use for the Mac mini itself along with 2 MacBooks

A couple questions:

1.) If I allow the Mac Mini to sleep with WOL and Powernap enabled will it wake when the MacBooks attempt to backup?
There are no bonjour sleep proxy devices on the LAN. I could set the Mac Mini to a static IP if that would help.

2.) When enabling the time machine shared folder I can set a max size per backup. Would this apply to only the MacBooks or would this limit the backup size of the Mac Mini also?

Thank you
 

Brian33

macrumors 6502a
Apr 30, 2008
810
64
USA (Virginia)
1.) If I allow the Mac Mini to sleep with WOL and Powernap enabled will it wake when the MacBooks attempt to backup?
There are no bonjour sleep proxy devices on the LAN. I could set the Mac Mini to a static IP if that would help.
I'm not an expert, but I think you do need a sleep proxy device on the network to wake the Mac Mini. But it should be easy enough to test it without the sleep proxy and see if it works! If not, and you don't want to leave the Mini on all the time, you could probably get a 2nd-gen Airport Express pretty cheaply and just have it in bridge mode (I assume you have a non-apple router and want to keep it that way).

2.) When enabling the time machine shared folder I can set a max size per backup. Would this apply to only the MacBooks or would this limit the backup size of the Mac Mini also?
IIRC the max size setting is in the Sharing section of the Mini's system preferences. I don't think it applies only to backups done to the shared folder by remote machines. That is, I don't think it will limit the size of the Mini's backups. I'm basing this guess on the fact that it's in the Sharing section, but the Mac Mini will not be using its own SMB services to access that directly-attached drive...
 
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nicho

macrumors 68030
Feb 15, 2008
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IIRC the max size setting is in the Sharing section of the Mini's system preferences. I don't think it applies to backups done to the shared folder by remote machines. That is, I don't think it will limit the size of the Mini's backups. I'm basing this guess on the fact that it's in the Sharing section, but the Mac Mini will not be using its own SMB services to access that directly-attached drive...
There are ways to limit the size of backups if so desired but they're a bit technical:

 
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macprobuffalo

macrumors member
Original poster
Feb 27, 2015
50
7
I ended up configuring it as follows:

- Set the Mac mini to never sleep
- Enabled HDD sleep
- Left the backup disk as a single partition. The Mac mini backs up at the root level. A single folder named “network backups” was created on the drive. This folder is shared as a time machine destination with a max size limit of 500gb per backup. The MacBooks backup to this.

Thinking back on this setup I can only hope that the Mac Mini system backup won’t grow so large that there isn’t 500gb available for each macbook. I can only hope Apple’s engineers thought of this and the mac mini system backup is automatically limited to
(HDD size) - ( macbook backup count * 500gb)

Edit- next time I have access to the computer I will complete the command in the link Nicho posted to limit the system backup. Seems pretty simple
 
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hobowankenobi

macrumors 65816
Aug 27, 2015
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on the land line mr. smith.
From the beginning, TM will use all the space allocated, and build history. So the user has to estimate how much space is needed, based on how much history one wants. Once the TM allocated space is filled, TM will automatically delete older data to make room for current backups.

For disaster recovery, typically users would want the latest version of everything....so hypothetically, one version (the latest version) is all that would be needed.

But not covered in that scenario is if a file gets damaged, accidentally deleted, or otherwise mangled, and one wants older version(s) of documents. For that, multiple copies are needed, and so more space is needed for backups than for live data.

That brings us full circle to: how much space? Some say a good rule of thumb would be double the TM space of live data. More space = more versions.

The hard part is, TM deletes the oldest files automatically. So how many copies (going how far back?) does one have?

TM does not allow this to be set. The only easy answer is give it more space.

Most enterprise grade BU software would let users set:

A: number of copies saved
B: amount of time to retain documents (once the original is deleted)
C: both A and B

Unless there have been recent updates to TM, it allows nether to be set by users.

All the above (and a few other things) are why I switched to a Synology NAS, and use their Drive backup/sync tool instead of TM. While it does have its own quirks and shortcomings, I wanted the version control and autodelete features, not to mention it seems to do much better over wifi and even over a WAN...both of which are problematic with TM, or at least have been in the past.

Synolgoy version control:

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