Is there a limit on the number of Macs that can use a single 2TB Time Capsule?

Question

I am looking at buying a few of the 2TB Time Capsules for our office, where we have about 20 unibody MacBook Pros with 128GB SSDs.

Is there a limit on the number of Macs that a single 2TB Time Capsule can provide Time Machine backup targets to? Does anyone have advice or experience regarding using a Time Capsule as a target for multiple machines?

Answer 1

According to this post on Apple's product page for the Time Capsule, up to 100 machines can use a single Time Capsule. The source of the "100" is not accredited, so it may not be accurate.

Answer 2

There shouldn’t be any technical limit other than hard drive space. Each backup gets stored in different directories inside the volume. However, I’m sure you’d start running out of space fast if you have more than two-three machines that actively create/edit data.

Answer 3

I would take care with having several Time Capsules as you will then have several Wireless networks and you need to work out how they interconnect.

It might be better to get some NAS and run Time Machine on that e.g. Netgear or even a Mac and run OS X server on that.

Answer 4

I use a LaCie d2 Quadra Hard Disk with TimeMachine and have so far backed up 6 different machines with it and recovered 2 times. I don't know if there is an upper limit.

Answer 5

This is a very workable solution. There is no built in limit and you can look over the system logs to see if any machines take too long to back up due to slowness and lighten the load on any one Time Capsule as needed.

For some people it's ideal, very maintainable, and drop dead simple to plan and support.

You can use BackupLoupe to look into the individual backups to see what files are changing and estimate how fast each Mac is filling up the space on the backup drives. You could use one Mac connected to the Ethernet port to scan the files without any WiFi delays and once scanned, you have the information on that Mac to examine "offline". You can mount the volumes and scan them as needed to update them as time passes - maybe once a month to check on things.

Do run a comparison on how much it would cost to buy a Mac mini server and use it to back up everything in one spot instead of several Time Capsules. You could then save money on the networking with Extremes and Expresses and have better expansion options. I would guess this is more cost-effective and easier/more powerful if you are buying three Time Capsules and might even be better even if you only are buying two Time Capsules.

Setting aside the cost of the initial hardware, a back of the napkin comparison might look like this assuming you need the TC for WiFi networking as well as backup functionality:

1. Three Time Capsules

   • Easier to set up initially (if you guess well or over-buy storage you may never need to maintain which Mac backs up where minimizing maintenance)
   • Takes more time to plan and track which Mac backs up where
   • Harder to predict when space will run out
   • Add space in increment of new Time Capsules (pricier storage)
   • Takes more time to track / reconfigure clients when adding more space (especially if you intend to move the previous backup to the new TC and don't want to cut that user off from their backup history)
   • TC backups are harder to backup, archive, or move around (if you even need this)

2. One Mac mini + Airport Extreme + optional AirPort Express to extend the network

   • Harder to set up initially (maybe one day's reading, learning, and doing)
   • No hassle or time to shuffle or track which Mac backs up where
   • Easier to predict when space will run out
   • Can add more space by adding more drives (less pricey storage)
   • No need to reconfigure clients as more space is added
   • Very easy backup of the server and backup data (if you even need this)

You can minimize the work on maintaining a fleet of Time Capsules by periodically backing up each Mac to a connected HD and then deleting the backup for that Mac and starting Time Machine fresh. Rolling those with 1/4 of the Macs every three months will spread the work and let each Mac generally have a year of history before it gets erased and starts anew.