(Custom Build) Super Time Capsule - am I missing something

Question

I received an interesting request today. Namely, is it possible to setup a networked Time Machine to backup the Desktops of 11 workstations on a LAN.

While I'm familiar with OSX, I haven't attempted to setup Time Machine until today.

I work with a group of professional photographers/videographers/graphic artists that regularly produce a large volume of products. They already have a large (ie 30+TB) NAS they use to archive old projects but there are cases where some deliverables were accidentally deleted prior to backup.

The Hardware:

• A Mac Mini loaded with Mavericks
• OSX Server
• 5TB of SAN

The Setup:

• Load OSX Server on the Mini
• Mount the SAN via iSCSI
• Partition the SAN with 2 Volumes, Storage & Backup with a 3:1 ratio
• Setup OSX to backup using Time Machine
• Create one folder for each workstations desktop on the Storage volume
• Share the Storage volume via SMB

Note: iSCSI allows the OS to transparently mount a networked SAN as a local disk.

On the workstations I'll create symbolic links to replace the user's local Desktop folder with the Desktop folder on the network drive.

Then, if a file is lost somebody can remote into the Mac Mini and wind back the Time Machine to recover any lost files.

The Mini will be dedicated to this and sharing printers alone so I don't think the backups will overwhelm the server. The SAN will be configured in a of Raid50 array with 2 drive redundancy. This setup will reside on a trusted, private, air-gapped network so security isn't an issue. All network connections are hard-wired.

Are there any special Time Machine quirks/limitations that I need to look out for before I invest the time and effort to build this beast?

Answer 1

I don't think you need to have one folder per workstation - each backup will be created in a .sparsebundle file, that is mounted by the remote workstation that belongs to it, and used as the backup disk.

At home I have a Mac Mini running OS X Server, and I also back up my MacBook Pro and my wife's MacBook Pro to it over WiFi. It works well, and apart from the size of the disk I imagine it would scale just fine.

Answer 2

I'm interested in a similar solution as the one you're describing, and from what I've read, this may be of interest for your setup:

• There is no native iSCSI initiator on OS X. There are alternatives. Xsan looks like the standard on OS X but I'm at a loss there.
• The Time Machine share or volume has to be set as AFP in order to work (you mention SMB, although it appears to be for storage purposes).
• OS X Server allows for Time Machine quotas and Yosemite clients will follow them (older OS X's won't). If the computers backing up to your server are older than 10.10.x they will eat all the available space with their Time Machine backups. One solution may be setting up multiples volumes, one for each Time Machine backup as to enforce the quota, or as you suggested, at least separating storage from backup on different volumes.
• If the backups are encrypted, only the owner –or a third person with the encryption password– will be able to see the contents of the .sparsebundle, so no need to put each backup on a different folder for that specific situation.
• Your proposed setup of the desktop (or any other user folder) to reside on the server and later being redirected via symlinks is not needed for the backup; simply configure each user to back up to the Mac Mini setting it up as a Time Machine destination with OS X Server. Then each user may enter Time Machine at will on their own systems, without the need to remotely login to the server and start Time Machine there.
• You can –if you wish– setup Network User accounts on OS X Server and have something like what you described: users having all their data stored on the server and accessing it no matter what computer they are using. A very good explanation and setup instructions can be found in this Ars Technica article.