Lots of simultaneous Time Machine users

[dtemp]

I've been running my own FreeNAS box at home for half a year now, and have had great success. Besides using it as a general-purpose file share, I'm also backing up 3 Macs with the Time Machine service.

I'm "the IT guy" at work and am considering proposing FreeNAS for when we grow out of our existing Time Machine solution. We have about 40 Macs in our office that backup (over WiFi) to a Mac Mini with Server.app installed and a thunderbolt Promise Pegasus2 R8 (which came with consumer 7200rpm drives). This actually works "fine;" I'm not interested in getting any more pure performance than the R8 since everything is limited to a gigabit ethernet connection and 802.11ac WiFi from 2 access points.

What I'm more worried about is the software side of things, if the AFP service can handle several dozen concurrent connections. Our office might double to 80, and with hourly backups, there might be 60 backups at certain times.

I'm wondering if anyone has any experience with similar Time Machine loads, if there are any essential software tweaks, or any hardware options you'd recommend. (FYI I don't think link aggregation would help much, seems like gigabit ethernet isn't a bottleneck.)

 

[anodos]

A couple of years ago I had to set up FreeNAS as a time machine target. I had problems with sparse bundles getting corrupted when doing backups over wifi. It was an intermittent problem (sometimes it would go a month, other times a week). The problem vanished when I switched to using ethernet. Granted this was in a developing country where the networking hardware I had available was nothing like in a western country.

 

[mjws00]

It would seem to me that there will be a LOT of overhead involved to do this well for 80 users. As you know for your existing small FreeNAS install. It's not just a couple clicks in a nice GUI ala Server.app. You are getting into the range where you should be thinking about proper centralized backup software. At that point I'm on a Windows server and probably not much use to you, sorry.

Might be a nice way to use the FreeNAS box as the backend storage, for your existing mini or a slightly beefier box. Maybe someone has pulled that off at scale. I wouldn't be concerned about AFP being able to handle the connections. I'd just wonder if the system multiplied 80x would be reliable and not a source of constant pain. Good luck I haven't seen anyone tackle this here before.

 

[cyberjock]

Honestly, a Mini could probably do 40 machines, but for 80 I'd seriously consider something beefier. That's a *lot* of data flowing around unless the Apple Time Machine has some indexing or something. I don't have much experience with Time Machine so I can't really say for 100% certainty. But I know if I had 40 machines running Acronis TrueImage the Mini would be able to do it, but you'd be bottlenecked at the NICs on the server.

 

[dtemp]

Thank you all for the responses. Seems that no one who has seen this post has tried a large amount of Time Machine users. (Maybe I should post to the Help&Support Forum? But Cyberjock has probably heard of someone with this many TM users if they exist...)

To be clear, I'm considering replacing the mini entirely with an appropriately-beefy FreeNAS box, although using FreeNAS as a sort of "DAS" for the Mini running a TM service is certainly an option if that works better (not sure why it would though).

There are currently signs of the Mini "straining." It takes 5-10min to load the Time Machine settings to be editable after launching Server.app (literally says "Loading" when you click on TM on the sidebar). File sharing services need to be bounced every few days because they become wonky in various ways.

One thing that won't be fixed is that all of these concurrently backing-up machines will be competing for WiFi spectrum. Obviously most of our WiFi traffic is TM backups and not internet traffic. It would be nice if they backed up a little less frequently, and although I know what .plist I would edit to do that, I'm not sure I want to introduce that setting for administrative overhead reasons.

Obviously FreeNAS can't do much if we're hitting some wifi limit or array HDD thrashing speed limit; my main question is stability and grace under fire. I just had to rip out some Ubiquiti UniFi units because they couldn't be stable enough in my office, so there is already a bit of egg on my face!

 

[cyberjock]

You don't need to post in another section. The regular posters look at the "new posts" section of the forum and will still see the thread.

Wifi is a poor choice for backups. Too much data and a disconnect usually means you have to start the transfer over. That's where laptop port replicators with wired ethernet come in really handy.

The reality is that Apple users are in the minority. By about 500:1. Most Apple questions seem to go unanswered and unsolved because almost nobody with extensive experience with FreeNAS uses Apple.

 

[dtemp]

All of our 40 laptops getting wired ethernet is literally the last thing that will ever happen at my office. It would probably cause more disconnects than dealing with the WiFi because everyone carries their computers around to couches and conference rooms. Plus it costs $100s per drop, plus a big Cisco switch. WiFi roaming is pretty seamless, and even though an ongoing ping might drop for 2 seconds, it seems like the backups are fine. Even if a backup fails, it will try again in a bit. Incremental backups are usually <1GB anyway.

 

[dtemp]

I'm in a skyscraper in Manhattan. If we don't get some overpriced union guy to run the drops, we'll have a giant inflatable rat outside on the sidewalk ;)