Drobo 2nd Generation & Network Time Machine Backups for Multiple Clients

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Level 3

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Drobo 2nd Generation & Network Time Machine Backups for Multiple Clients

We are a small business with 11 Mac clients on our LAN. We have a 2nd generation Drobo with four 2TB drives (8TB total). I want to run Time Machine backups over the network to the Drobo for all 11 clients. I've read various blogs and posts, and have come across quite a bit of conflicting information.

Does anyone here have any rock solid advice for me, preferably practical? Should I create 11 partitions on the Drobo, or will Time Machine sparse one volume according to the 11 clients it detects?

If creating the partitions is the most stable approach, do I need to put the 95% Drobo threshold cap on each partition?

I appreciate any help and advice.

Mac Pro (2 x 2.66 GHz Dual-Core Intel Xeon), Mac OS X (10.6.5), 10GB RAM Apple 24" LED Cinema Display

Posted on Jan 27, 2011 5:29 PM

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Answer 1

Pondini

Level 8

38,863 points

Jan 28, 2011 9:05 AM in response to Marc Dahmen

Marc Dahmen wrote:
. . .
Should I create 11 partitions on the Drobo, or will Time Machine sparse one volume according to the 11 clients it detects?

I have no experience with Drobos. There are a few posts in this forum about them, but little that addresses this.

For backups done over a network, each Mac's backups are put into a separate +sparse bundle disk image+ (backups done locally are stored in separate sub-folders in a single top-level folder).

You can do do it either way, but most likely want to let them all share a partition, since each will have a separate sparse bundle. They'll all compete for the same space, and coexist peaceably.

The only possible downsides are:

Once the partition is full, if you want or need to delete one Mac's backups entirely and start over, more empty space will be available briefly. The other Macs will tend to fill that space quickly, leaving less room for the new one to expand into, so it will likely have fewer old backups.
Adding a 12th Mac will be a problem (but ditto if you do it the other way, with 11 partitions filling the drive).
When you do need to delete a Mac's sparse bundle, it will take quite a while. If each is on it's own partition, you can just erase the partition (I assume you can on a Drobo).
There is a possibility you can limit the size of each Mac's backups, by changing the maximum size of each sparse bundle. See #A8 in [Time Machine - Troubleshooting|http://web.me.com/pondini/Time_Machine/Troubleshooting.html] (or use the link in *User Tips* at the top of this forum). As noted there, effective with 10.6.3, TM started automatically resetting the sizes, but stopped for some of us on 10.6.5 or 10.6.6, so even if it seems to work, I wouldn't depend on it.

If creating the partitions is the most stable approach, do I need to put the 95% Drobo threshold cap on each partition?

Again, I have no experience with Drobos. But Time Machine will automatically delete the oldest backup (for the Mac it's running on) when it needs room for new ones.

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Answer 2

etresoft

Level 9

56,698 points

Jan 28, 2011 9:43 AM in response to Marc Dahmen

Marc Dahmen wrote:
We are a small business with 11 Mac clients on our LAN. We have a 2nd generation Drobo with four 2TB drives (8TB total). I want to run Time Machine backups over the network to the Drobo for all 11 clients. I've read various blogs and posts, and have come across quite a bit of conflicting information.

This doesn't sound conflicting: http://www.drobo.com/productstimemachine.aspx
and: http://www.drobo.com/tipsandfacts/drobofact12.php

Does anyone here have any rock solid advice for me, preferably practical? Should I create 11 partitions on the Drobo, or will Time Machine sparse one volume according to the 11 clients it detects?

I think you just create one Time Machine partition and Time Machine will create multiple sparse volumes therein.

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Answer 3

Marc Dahmen Author

Level 3

862 points

Jan 28, 2011 10:17 AM in response to Marc Dahmen

Pondini,

Thanks for the helpful information. I think I'll go with the single TM partition and let TM worry about the sparse bundles. Seems like a lot less hassle than creating 11 separate partitions. FYI, Drobo has a 95% threshold cap. That other 5% it needs for processing the data that's on the drive through some proprietary system. This is done to prevent any loss of data as drives get full and you add more or bigger capacity drives.

Etresoft,

Of course you won't find any conflicting information on Drobo's on website. The conflicts I read were from real people in real life situations. There have been an equal amount of positive and negative comments about either approach to using an older Drobo for TM purposes. Now the DroboFS, to which you linked in your post, is a totally different story. That particular piece of hardware and the control panel it comes with was specifically designed for network TM backups. But we don't have $2,000 to drop on a new Drobo at this time.

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Answer 4

etresoft

Level 9

56,698 points

Jan 28, 2011 10:40 AM in response to Marc Dahmen

Marc Dahmen wrote:
Of course you won't find any conflicting information on Drobo's on website. The conflicts I read were from real people in real life situations. There have been an equal amount of positive and negative comments about either approach to using an older Drobo for TM purposes. Now the DroboFS, to which you linked in your post, is a totally different story. That particular piece of hardware and the control panel it comes with was specifically designed for network TM backups. But we don't have $2,000 to drop on a new Drobo at this time.

That is still not conflicting information. In this case, the information is that you shouldn't use Time Machine in this configuration. If you aren't using products the way they were designed and tested, you are pretty much on your own. May of the reports of problems are from people who are using Drobo and Time Machine in unsupported configurations. Drobo sells a Time Machine-friendly device for $2000. Apple has one for a lot less. If you try splitting the difference you will probably end up paying the same or more in lost time troubleshooting.

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Answer 5

Marc Dahmen Author

Level 3

862 points

Jan 28, 2011 10:48 AM in response to etresoft

etresoft wrote:
That is still not conflicting information. In this case, the information is that you shouldn't use Time Machine in this configuration. If you aren't using products the way they were designed and tested, you are pretty much on your own. May of the reports of problems are from people who are using Drobo and Time Machine in unsupported configurations. Drobo sells a Time Machine-friendly device for $2000. Apple has one for a lot less. If you try splitting the difference you will probably end up paying the same or more in lost time troubleshooting.

The conflicts to which I was referring are from blogs and other tech support articles that I read yesterday. To say there is no conflict implies you read the exact same things I did, and that would imply omniscience on your part. Yes, we have an older Drobo and yes we will be attempting to use it in what is possibly a non-supported way. That is why I did my research and that is when I found conflicting stories with varying degrees of success and failure. Hence my original post, in which I was looking for someone on this forum who could give me real life, practical advice on his own experience doing what I will be attempting to do.

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Answer 6

etresoft

Level 9

56,698 points

Jan 28, 2011 11:08 AM in response to Marc Dahmen

Marc Dahmen wrote:
The conflicts to which I was referring are from blogs and other tech support articles that I read yesterday. To say there is no conflict implies you read the exact same things I did, and that would imply omniscience on your part.

Omniscience is easy. It is the omnipotence I'm still working on.

Yes, we have an older Drobo and yes we will be attempting to use it in what is possibly a non-supported way. That is why I did my research and that is when I found conflicting stories with varying degrees of success and failure. Hence my original post, in which I was looking for someone on this forum who could give me real life, practical advice on his own experience doing what I will be attempting to do.

There are so many factors that would affect your situation that I'm not sure anyone would be able to give you good advice. I know how Time Machine works and I'm a big fan of it. It has never failed me and I've not had any problems with it. I don't think my experience would be applicable to you. Considering the funky things that Time Machine does internally, perhaps it isn't the best solution for you. Maybe Carbon Copy Cloner or SuperDuper! would be better. There are a number of people here on Apple Discussions who wouldn't touch Time Machine and swear by those two programs. Personally, I think they are nuts. But if you aren't even starting from a supported configuration, then I can't recommend Time Machine at all. Its utility comes from its reliability and ease of use. You aren't going to have either, so Time Machine isn't going to be useful for you.

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Answer 7

Marc Dahmen Author

Level 3

862 points

Jan 28, 2011 11:17 AM in response to etresoft

etresoft wrote:
There are so many factors that would affect your situation that I'm not sure anyone would be able to give you good advice. I know how Time Machine works and I'm a big fan of it. It has never failed me and I've not had any problems with it. I don't think my experience would be applicable to you. Considering the funky things that Time Machine does internally, perhaps it isn't the best solution for you. Maybe Carbon Copy Cloner or SuperDuper! would be better. There are a number of people here on Apple Discussions who wouldn't touch Time Machine and swear by those two programs. Personally, I think they are nuts. But if you aren't even starting from a supported configuration, then I can't recommend Time Machine at all. Its utility comes from its reliability and ease of use. You aren't going to have either, so Time Machine isn't going to be useful for you.

I am a big proponent of Time Machine as well. We use it in our Graphics Department for the Mac Pros with multiple hard drives. It works great and has saved us several times already. I have also had great success with Carbon Copy Cloner, but I'm looking for a more seamless network solution for the other client computers. We are currently using Retrospect to backup select data on those clients, but we want to move away from that application and use Time Machine to back up the entire client computers' contents. The end users are not very computer savvy, so I'm hoping Time Machine will be the best behind-the-scenses approach for them to quickly recover data they may have accidentally deleted or lost.

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Answer 8

Pondini

Level 8

38,863 points

Jan 28, 2011 12:10 PM in response to Marc Dahmen

Have you considered running OS X Server? I'm only vaguely familiar with it, but it has a number of features that might be better for your situation. The software is $499, or you can get a mini with it pre-installed for $999.

Among other things, it allows you to manage workgroups, and control Time Machine backups from the server, including limiting the amount of storage used. (They recommend excluding system folders and applications, which I think is nuts, though.)

See: http://store.apple.com/us/product/MC588Z/A?mco=MTY3ODQ5OTY

and: http://www.apple.com/server/macosx/

and for all the nitty-gritty: http://images.apple.com/server/macosx/docs/UserManagementv10.6.pdf

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Answer 9

Marc Dahmen Author

Level 3

862 points

Jan 28, 2011 12:18 PM in response to Pondini

Pondini wrote:
Have you considered running OS X Server? I'm only vaguely familiar with it, but it has a number of features that might be better for your situation. The software is $499, or you can get a mini with it pre-installed for $999.

I am getting ready to implement our new Mac Mini server, which is one of the reasons why I started this thread. Right now we have our Drobo hooked up to our G5 Xserve, and we're running Retrospect client backups onto the Drobo, with the Retrospect Server app running on the Xserve. I want to keep our new Mini server lean and clean, so I don't want the whole office doing Time Machine backups to it. I was pulling to get a Mac Pro with OS 10.6 Server so we could install and RAID a few more hard drives and then implement network Time Machine backups to it through the Server OS. But I was out-ruled.

I'm going to try the single-partition approach to the Drobo, making sure to account for it's 95% threshold amount, and see how the TM network sparse bundles work out for us.

Thanks for everyone's help.

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Answer 10

etresoft

Level 9

56,698 points

Jan 28, 2011 1:13 PM in response to Marc Dahmen

Marc Dahmen wrote:
I want to keep our new Mini server lean and clean, so I don't want the whole office doing Time Machine backups to it.

An Apple Time Capsule only has a 500 Mhz chip and 128 MB RAM. Your Mini should have plenty left over and you could connect the Drobo directly.

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Answer 11

Feb 17, 2011 2:41 AM in response to Marc Dahmen

I am about to put a Drobo FS on our home network and would be interested to know hoe you got on with this set up. Creating one big Time Machine Share and letting all the networked machines gradually fill it with their sparse bundles sounds like a good efficient way of using space.

However, "DroboFact #12" <http://www.drobo.com/tipsandfacts/drobo fact12.php> suggests you should create a size-limited share for each machine to back up to. That sounds sensible in terms of keeping things separate, but means reserving a huge amount of empty space (e.g. 1Tb for each machine) and is it really necessary?

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