Multi-Macintosh Time Machine Backups

[nello]

I followed these instructions for setting up FreeNAS for a single user with Time Machine:

http://www.freenas.org/images/resou...as8.3_guide.html#__RefHeading__9150_381758029

Works perfectly!

Now, how do I extend this to cover multiple Macintoshes?

Thank you for your help.

- nello

 

[interpeix]

My advice if you have 5 o less Macs, make one AFP share for each one and assign quotas.

 

[nello]

...make one AFP share for each one ....

But doesn't the disk discovery have to be designated "Time Machine" in order for time machine to connect to it? And I thought that you weren't supposed to have more than one share with Time Machine discovery.

- nello

 

[JaimieV]

Time Machine will only show shares designated as TM in its "pick a disk" GUI, but you can manually mount any share and use it as a TM destination then.

FreeNAS *should* be able to share multiple TM destinations, but netatalk is buggy and won't do it right.

Back to the original question - I've got one TM share (of a dataset with a 1Tb quota), and backup four Macs to it. TM doesn't share equally by any means, but each Mac does cope fine when the 1Tb fills up, trimming its own backups inside its own virtual disk image (.sparsebundle) on the share. TM is designed to cope with exactly that situation, it's what happens with a Time Capsule - they only have one TM share by default.

So, your choice! You can setup separate quota'd shares for each machine, but you'll have to forego the handy 'TM advertising' feature if you do, at least until netatalk3 comes into FreeNAS.

 

[nello]

You can setup separate quota'd shares for each machine, but you'll have to forego the handy 'TM advertising' feature if you do, at least until netatalk3 comes into FreeNAS.

So, each share corresponds to a dataset, right? So, I'd be setting up a separate dataset for each machine and that's where I'd set the quota, right?

- nello

 

[JaimieV]

Yes, sorry - I was being unclear. Spot on.

 

[nello]

Yes, sorry - I was being unclear. Spot on.

And just to be clear on my part...

I'm not being pedantic. I just need to take it in baby steps now as I'm new to FreeNAS (and FreeBSD for that matter).

Thank you!

- nello

 

[JaimieV]

Absolutely, always double check if something is unclear. Usually it's a bad description, or bad assumptions. Hope it works well for you. (I'm still sticking with the one TM share, personally!)

 

[nello]

Time Machine will only show shares designated as TM in its "pick a disk" GUI, but you can manually mount any share and use it as a TM destination then.

I like the idea of creating a separate dataset and share for each user's TM.

I'm sorry to be so dense, but how do I use a regular share as a TM destination?

- nello

 

[fracai]

Just to add a data point here, I'm backing up two machines with TimeMachine to my FreeNAS box where each machine has its own dataset and share point. Both are advertised as TimeMachine shares. I had some initial trouble getting everything connected (I was trying to connect to AFP://share instead of AFP://freenas/share), but I haven't had a single problem since.

To use a regular share, I think you can mount it normally and then drag it into the TimeMachine pref panel when selecting the backup destination. Another, more explicit method, is to use 'tmutil' on the command line. See the 'setdestination' command at: http://developer.apple.com/library/mac/documentation/Darwin/Reference/Manpages/man8/tmutil.8.html

 

[nello]

To use a regular share, I think you can mount it normally and then drag it into the TimeMachine pref panel when selecting the backup destination.

I'm sorry but all the ways I've tried to drag/drop don't work. Would you mind posting a screen shot of what you propose?

Another, more explicit method, is to use 'tmutil' on the command line. See the 'setdestination' command at: http://developer.apple.com/library/mac/documentation/Darwin/Reference/Manpages/man8/tmutil.8.html

I gave that a try and it doesn't work either

Code:

Descartes:~ nello$ sudo tmutil setdestination afp://userName:password@ddnsFQDN/share 
Password:
Destination does not support lock stealing. (error 45)
The backup destination could not be set.
Descartes:~ nello$

Any idea why I'm getting this error? (Yes, I used the real values for "userName:password@ddnsFQDN/share"; changed them in this post for privacy.)

I'm running OS X 10.8.2 (12C3006).

Thank you.

- nello

 

[JaimieV]

You can also see normal shares that you have already mounted, directly pickable in the TM browser box if you enter the following line in the Terminal:

defaults write com.apple.systempreferences TMShowUnsupportedNetworkVolumes 1

which does exactly what it looks like it does.

 

[fracai]

Ah, maybe you can't drag them in. I haven't done this in a while, and when I have most recently it's been on the command line, so I think the key is the defaults command that JaimieV posted.

As for the tmutil tool, do you have your share advertised as TimeMachine? The error is basically telling you that the share doesn't support everything that a TimeMachine backup requires and it'd be my guess that that is due to how the share is advertised by Netatalk.

Can you mount that volume in the Finder using "Go > Connect to Server"? Just paste in the AFP://host/share part and you should be prompted for the user name and password.

 

[nello]

You can also see normal shares that you have already mounted, directly pickable in the TM browser box if you enter the following line in the Terminal:

defaults write com.apple.systempreferences TMShowUnsupportedNetworkVolumes 1

which does exactly what it looks like it does.

But the Time Machine command line says that the share does not support "lock stealing":

Code:

Descartes:~ nello$ sudo tmutil setdestination afp://userName:password@ddnsFQDN/share 
Password:
Destination does not support lock stealing. (error 45)
The backup destination could not be set.
Descartes:~ nello$

Isn't that a problem?

- nello

 

[nello]

Why the warning if it is okay to ignore it?

As for the tmutil tool, do you have your share advertised as TimeMachine? The error is basically telling you that the share doesn't support everything that a TimeMachine backup requires and it'd be my guess that that is due to how the share is advertised by Netatalk.

You are correct that I hadn't enabled "Time Machine" as the Disk Discovery Mode on afp://ddnsFQDN/share

Now that I've enabled it, command tmutil setdestination works without error.

I've also gone ahead and enabled multiple shares with the "Time Machine" Disk Discovery Mode and all show up in the Time Machine GUI.

So, it looks like at least two AFP shares can be advertised as Time Machine capable even though there are dire warnings about doing so:

Code:

Note! Selecting 'Time Machine' on multiple shares may 
cause unpredictable behavior in MacOS. Default mode exports 
the volume as a data volume for users.

Ignoring this explicit warning makes me nervous. Am I just being silly?

Can you give me any sort of explanation for why the warning is there but ignoring it will result in robust backups? (As robust as Time machine can produce.)

Thank you.

- nello

 

[fracai]

I can't really comment on the warning. I tried looking for more info, but couldn't find anything. I've been using this configuration for several months now without error. I can only assume that there is some circumstance that causes problems that I, and maybe the average user?, just haven't run into. Maybe it's just a CYA flag.

 

[nello]

Multiple TM Shares OK Until TM Runs Out of Space and Starts Trimming?

I can only assume that there is some circumstance that causes problems that I, and maybe the average user?, just haven't run into.

Have any of your Macs filled their quota?

http://doc.freenas.org/index.php/Apple_(AFP)_Shares#Using_Time_Machine

Code:

due to a limitation in how Mac deals with low-diskspace 
issues when multiple Mac's share the same volume, selecting 
"Time Machine" on multiple shares is discouraged as it may 
result in intermittent failed backups

Maybe that's the condition in which the problem appears.

- nello

 

[JaimieV]

I suspect that warning is out of date - at least, I've tested that exact scenario with 10.8.2 and had no issues at all; the Macs saw that they had to trim their backups and did so without problems. One of the Macs was 10.6.8 and that didn't have a problem either, come to that. I may have just been lucky.

That warning you saw is strange, implies that there's a lack in the AFP protocol that FreeNAS runs, but there isn't as using even a normal share from FreeNAS works fine... I may do some investigation around that.

 

[nello]

I suspect that warning is out of date
... I may do some investigation around that.

Thank you!

That would be appreciated by those of us who do RTFM.

- nello

 

[JaimieV]

Watch this space - it'll take a few days though.