A month ago I posted on my experiment with a Home made Time Capsule and I’ve learned some things and changed some things since that long post.
First let me say that while I think this setup is fantastic and every Mac user should be doing something like this, this is not my only method of backing up my computer. I’ve continued to use SuperDuper to do a complete clone of my computer every day.
This setup worked perfectly, when it worked. Time Machine works in the background so the only way I knew it was working or not was to check it’s system preference pane from time to time to see when the last backup was. Time Machine is supposed to attempt a backup every hour when the computer is awake and connected to the network but I was noticing that there were times when it was skipping 1/2 a day at at time.
Something was up. So, I left the system preference pane open so I could watch what was happening. I watched as Time Machine attempted a backup but the drive never spun up and mounted. If I unplugged and replugged the USB cable of the drive it would spin up and Time Machine would find it and work.
I wasn’t sure what the problem was but I had a feeling that the portable USB 3 bus-powered drive I was using wasn’t getting the wakeup message from Time Machine, either because USB 2 (what’s on the AirPort Extreme) or the drive itself was missing the intelligence to wake the drive from sleep at the needed time.
Bus-powered drives tend to be 2.5″ HD mechanisms for portability and these smaller mechanisms don’t need as much power to run so can run off of the power in a USB cable connection to a computer (they’re what are inside laptops as well as portable cases). Desktop drives tend to have 3.5″ HD mechanisms in them and have power bricks. And, they cost less for a lot more storage.
I thought maybe a desktop drive might solve this problem but I decided to pass this question (bus powered or desktop) on to someone I knew had a similar setup on his home network. He’s a developer who I met online many years ago through a mutual friend but who I’ve never met in person: Scott Gruby (this seems to be quite common these days).
Scott agreed: the bus powered drive was probably the problem and a desktop drive might solve it. He uses a Western Digital RAID drive on his network and I don’t need RAID but decided to look into their standard desktop drives. The Western Digital My Book seemed like a good way to go. 4TB for about $110 and decent reviews on Amazon. Its a larger case with a 3.5″ 4TB drive in it, no fan, and a power brick.
Given that there are many drives in this category I decided to take a look at the BackBlaze Hard Drive Reliability Review for 2015. Interestingly, in 2014 Western Digital was their most reliable drive but in 2015 it had been overtaken by Seagate.
In looking through the Amazon reviews of the Seagate 4TB desktop drive I noticed one comment/review that caught my eye. A Mac user attempting to use the drive as I am, connected to an AirPort Extreme for Time Machine over the air backups. He found that the drive did not mount on time for the backups to work. So, for me, that eliminated the Seagate and I ended up with the WD 4TB My Book for Mac. The Mac and non-Mac version cost the same so I figured I’d get the one with “Mac” on the case. I partition and format all of my drives so it doesn’t matter to me if the drive comes pre-formatted for the Mac.
The new drive came, I formatted it and got it connected to the AirPort. It’s very quiet, no fan and the spinning drive makes very little noise. I can hear it but it’s not obnoxious.
I decided to start from scratch and redo the Time Machine backups of both my wife’s MacBook Air and my MacBook Pro on the new drive. I started with my wife’s machine because it doesn’t have much on it. The initial backup took about 2 hours and worked flawlessly. Over the next two days my wife’s computer backed itself up to the new drive every hour. The drive went to sleep, then awoke for the backup every time. This was great, exactly what I was hoping for.
Then I started the initial backup of my MacBook Pro. Estimated time: 12 hours.
The great thing about Time Machine is that even on the initial backup I was able to close my computer (stopping the backup) and move to a different part of the house, open my computer (continuing the backup) until the initial backup was done.
Over the next few weeks I’ve kept track of Time Machine’s system preference pane on both my computer and my wife’s and the new drive is spinning up and mounting every time. If both machines want to back up at the same time Time Machine knows to form a line (so to speak).
I think the power supply of a desktop drive is probably essential for this application, but, there must also be something in each drive’s controller that allows it to be awaken by Time Machine. I can’t say that I’ve tested other desktop drives at this point but I take that Amazon commenter at his word that the very popular Seagate drive didn’t work for him. It might be that other brands work, I don’t know but I do know that the drive I got has been flawless so far.
Time will tell.