Forcing your Mac to wake up for SuperDuper! backups during the night

Posted by Pierre Igot in: Macintosh
June 20th, 2006 • 8:56 am

I have been using Shirt Pocket’s SuperDuper! for daily backups for a while now, and am very pleased with it, so much so that I have been recommending it to other users.

Its user interface is not perfect, but it doesn’t have a myriad of options, so it’s fairly easy to figure out exactly how it works in very little time and to set things up so that it automatically does a daily backup of all your important stuff to an external FireWire hard drive or another internal hard drive.

One thing about my home office setup, however, is that my G5 never goes to sleep. The displays go to sleep after about 15 minutes, but the computer itself is configured to never go to sleep, and the hard drives don’t go to sleep either.

Why did I make that choice? Well, the primary reason is that I am still on dial-up for my Internet connection, and that means that downloading large files is a royal pain in the neck. I need to be able to use the Internet for other things during the day time, so when there are things that I need to download, I put them in a queue in Speed Download and then, before I go to bed, I start the download queue and let Speed Download do its thing during the night, downloading big files one after the other.

(I should also note that I have a second phone line just for the dial-up connection, and unlimited access to the Internet with my Internet Service Provider. So I can stay on-line all the time and can still use my other phone line for regular phone communications.)

Fortunately, my home office is in a separate room and I can close the door during the night, which is enough to block the noise of the computer equipment. (The heat generated by the computer equipment also keeps the office reasonably warm, even during winter months with no other source of heat in the room with the door closed.)

But I have friends and colleagues who do not have that luxury and have to live with the noise of their computer equipment in the main living area in their house. For them, it is important to be able to put the computer to sleep when they are not using it, so that they don’t have to endure the noise more than is strictly necessary.

However, once you put your computer in deep sleep mode with the “Sleep” command, the OS becomes unable to execute scheduled tasks. This means that, if you use SuperDuper! to schedule a backup at 3:00 am, and you put your computer in deep sleep at 9:00 pm so that you can read a book in a quiet environment in your living room, the scheduled backup will not take place unless something or someone wakes the computer up some time before 3:00 am.

And that’s where the “Energy Saver” preference pane in Mac OS X’s System Preferences application comes in handy. In the bottom-right corner of the “Sleep” tab, there is a button labelled “Schedule…

This button brings down a dialog sheet with two options: one to “start up or wake” the system on any given day at a given time, and one to shut the system down or put it to sleep on any given day at a given time.

In our case, we can actually use the first option to force the computer to wake up from its deep sleep state some time before the backup is scheduled to take place, at 2:55 am, for example. And then we can use the second option to put the computer back in deep sleep mode after the scheduled backup has taken place, at 3:30 am, for example.

Of course, this does not really help if you happen to sleep in the same room as your computer. In that case, you probably do not want your computer to wake up from deep sleep at 2:55 am in the morning to do its backup.

But if you don’t actually share a bedroom with your computer and just want to be able to put the computer to sleep in the evening and not have to remember to wake it up before you go to bed, or want to save as much energy as possible by keeping the computer in deep sleep mode during the night except for the period when the scheduled backup is supposed to take place, then using the “Energy Saver” preference pane’s scheduling options might just be the solution for you.

(Another solution would obviously be to schedule the backups during the day time. On a fairly fast machine such as my G5 Quad, the computer remains quite usable even during a backup. But there is a performance hit just the same, and it might be more noticeable and intrusive on less powerful computers.)

Please note that I haven’t actually tested this myself, since, as indicated above, I do not put my computer to sleep at night. But on computers that do support the scheduling options in “Energy Saver,” I don’t see why this shouldn’t work.

With cheap external FireWire hard drives, and a very affordable and user-friendly product such as SuperDuper!, there is really no excuse for Mac users not to have a daily backup set-up in place. As a Mac tech support person, I have just seen too many people lose all their data after a hard drive crash because they didn’t have any backups. Don’t take the chance! For two or three hundred dollars, you can have a great automatic backup solution that will bring you considerable peace of mind. Is it not worth the extra expense?

(Of course, backups to an external FireWire hard drive are not a panacea. While simultaneous failure of two different hard drives is unlikely, you can still lose all your equipment at once in a house fire, or get all your computer equipment damaged at the same time by a nasty power surge or thunder storm. This means that you should still have regular backups in a remote location. I usually back up all my important stuff on DVDs and ask my wife to store them in her office at work. But there are of course several alternatives.)

3 Responses to “Forcing your Mac to wake up for SuperDuper! backups during the night”

  1. ssp says:

    Not to contradict you at all, just to remark that this is a remarkably old feature. IIRC even System 7.5 could handle automatic powering up and Apple’s hardware (without mechanical power switches) since that time has supported this as well. Back then I liked using a sound file as a startup object to make the computer work as an alarm clock :)

    Doing backups while working probably is a bad idea, particularly when essentially just copying things over as SD seems to do. Having as few files as possible change or move while the backup is taking place, probably is a good idea in that situation. And while making the backup may not use too much CPU power, at least on machines with slow drives (portables, say) will certainly hurt performance significantly.

  2. Pierre Igot says:

    Yes, I know this is actually a fairly old feature. However, I had never used it myself and I suspect that there might be other system administrators with their machines always on that never use it either.

    I do remember, however, experimenting with it a bit in the good old days prior to Mac OS X, and in my (admittedly fallible) memory there are doubts about whether it was all that reliable on older Mac hardware. I think I remember trying it on a given machine and noticing that it never actually did start up when it was scheduled to do so. But that was a long time ago, and I can’t even remember with what Mac model it was.

    I am assuming that these days it works reliably on all Macs.

    I agree that backups while working is not an optimal solution. However, if you do incremental backups, the software just copies the files that have changed, and that doesn’t necessarily take very long and require much CPU/HD activity. In addition, while the backup might not be 100% reliable and might miss a few files that change during the backup process itself, it’s still much better than having no backups at all.

  3. ssp says:

    Oh, sure it’s better than nothing but with OS X and its hundreds of thousands of files even traversing the whole file system is an effort. The area where I’d be most sceptical about a ‘backup while using’ strategy are applications like Mail. With its thousands of files to store your mail I assume you could easily end up in a situation where the index files in your backup don’t match the actual message files. While I assume that you should be able to recover everything nonetheless, just making sure things work correctly will require a lot of extra testing and scrutiny.

    I’ve never seen the automatic power on fail on the macs in our house, so I’m quite happy with that. Since having portables I haven’t really used the feature though as they’re quiet enough to just let them run through the night if that’s needed.

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