Re: Time machine backups

On Wed, 8 Jan 2025 02:49:11 -0000 (UTC), Lars Poulsen
<lars@cleo.beagle-ears.com> wrote in
<slrnvnrpt7.2oheu.lars@cleo.beagle-ears.com>:

On 2025-01-07, vallor <vallor@cultnix.org> wrote:

Bought a 4TB external USB/NVME device for my workstation. Installed
Samba and configured it to use the "fruit" module to offer up a Time
Machine share for the Mac Studio. (Also using it with Timeshift on the
workstation itself, but that part was easier.)
>
(Backups are good; automated versioned backups are better.)

 
I have setup "time machine" backups on two of my servers, using rsync to
a local external drive, but I have not figured out how to do it to a
Samba share. On the local external drive, using ext4 file system, hard
links make it very space efficient, but I don't think you can do that
with a Samba mounted remote drive. Any hints? Do you run the rsync on
the file server, so that you can do the hard links on the backup drive's
ext4 file system while the backup server sees its production client as
the remote Samba mount?
 
And is there a way to use a cheap remote "storage box" that is only
accessible as a Samba NAS as the versioned storage medium with similarly
good storage efficiency?

I'm not doing anything on the backend except provide the
Samba share.  MacOS Time Machine has it's own format
for storing versioned data, which is fairly opaque when
looking at the files on the backend filesystem.

Here's the web page with the recipe I followed:

https://blog.jhnr.ch/2023/01/09/setup-apple-time-machine-network-drive-with-samba-on-ubuntu-22.04/

I _assume_ it's space efficient, with either incremental or
differential backups -- but I'm watching it carefully to make
sure that turns out to be the case.

Our Mac Studio is named "Mac Studio".  On the server side, I see
in the share's directory a subdirectory, "Mac Studio.sparsebundle",
which contains various files and directories, including one
named "bands".  That directory contains multiple files of length
536870912 bytes, which would seem to be the backup(s) themselves,
in a structure managed by MacOS.

I'm also using Timeshift (not Time Machine) on my Linux
workstation, which backs up directly to the ext4 filesystem
on the external drive with rsync.  I'm pretty sure that uses
hard links to be space-efficient.  (It would be even better
and faster if it hard-linked directories, but that's not a
BCP for Unix.)

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