Wireless local backups for a PC and a Mac


The Challenge

Set up a local backup system that can reliably backup both a PC and a Mac … wirelessly.

The Tools

Pogoplug Series 4

Western Digital 1TB notebook (2.5″) hard drive

Kingwin EZ-Connect SATA-USB adapter

SuperDuper Mac cloning software (we’ll only need the free version)

GetBackup for Mac (we’ll need the pro version)

Cobian Backup for PC (free)

GParted (a free partition editor)


I want an initial clone of the Mac.

I want to do the initial backups with the drives connected locally, then incrementals wirelessly. (Full backups over wireless suck!)
Because I ended up formatting the drive with an ext3 partition, this was not possible. See below for details.

The Steps

There are two reasons why we need the SATA-USB adapter: 1.) the hard drive needs to be formatted. 2.) we want to do the initial backups with the drive connected locally. The Pogoplug doesn’t allow you to connect your Mac/PC directly to it and use the attached drive as a local drive. Again, this didn’t end up being possible.

Because I want a one-time clone of the Mac, I needed to format one partition using the Mac and another one using the PC GParted…

Using the adapter, plug the hard drive into your Mac. I used Disk Utility to create a 250GB “Mac OS Extended Journaled” partition on the drive. Why? Because SuperDuper requires this type of partition to clone a drive.

Now plug the drive into your PC. Using Disk Management GParted (more details below), create a 750GB NTFS ext3 partition on the drive. Why? Because this is the partition that the Pogoplug will write to. But why NTFS? Well, it was the least worst option:

  • Mac OS partitions can’t be read by Windows.
  • exFAT works on both Mac and Windows, but Pogoplug can’t use it. Damn! Would’ve been a good choice.
  • FAT32 could’ve been an option, but it doesn’t support files larger than 4GB. I have a feeling our backup files will be larger than that!

So that leaves us with NTFS. Macs can’t create NTFS partitions with Disk Utility, and by default they can only read from them. But with a special hack, you can make them read from and write to them (more on that later). Bottom line, NTFS was the least worst option. Just make sure you give the partition a simple name, like “NTFS”.

Now the disk is ready for our initial local full backups.

Plug the drive back into the Mac. Download SuperDuper and follow the instructions to clone the hard drive to the Mac OS partition. It’s very simple to use. And since we don’t need any of SuperDuper’s advanced features, it’s free! Woohoo, we now have a full clone of the Mac’s hard drive!

Hold up, a little detour here. What I had intended to do, perform the initial incremental backup (a.k.a. “full”) with the drive connected locally to either the Mac or the PC, didn’t pan out. After a few weeks of backups, it quickly became clear that PogoPlug’s support of NTFS is super-buggy. The drive was constantly corrupted. So I ended up burning GParted onto a CD, booting it up on my PC, and formatting the NTFS partition as ext3, a native Linux partition scheme. From my online research, PogoPlug doesn’t stably support the newer ext4 scheme, so ext3 seems to be the safest bet. Don’t use programs like ExtFS and EaseUS that claim to allow you to create/access ext3 partitions directly from Windows. They didn’t work for me and ended up corrupting my drive (luckily GParted doesn’t just create partitions, it can repair them too.) So stick with GParted for creating your ext3 partition. You can now skip ahead in these instructions and install Samba FIRST, then come back and do your initial incremental backup (a.k.a “full”) wirelessly. Yes, it’ll be slow, but since you can’t safely connect an ext3 drive directly to a Mac or PC, you’ll have to bite the bullet on this one and just let your computer crank on the initial backup for many hours (or days!).

Now onto the incremental backup of the Mac. Remember, we’re going to do this with the drive connected locally. Why? Because incrementals always start with a full backup. And full backups over wireless are TOO SLOW!

Download GetBackup. You’ll need to upgrade to the Pro version (20 bucks) because we’ll obviously be using the Incremental feature.

Hold up, we still can’t write to the NTFS partition. Macs actually have this ability but for some reason it’s disabled by default. So follow these steps to enable NTFS writing. (Note that the fstab file that is mentioned in the article did not exist on Snow Leopard, so I had to create it. Another similarly named file fstab.hd existed, but I left it alone at the advice of some other article.)

Create a folder on the hard drive called “MacBackup”. GetBackup allows you to click on icons that represent commonly backed up areas: Documents, Music, Photos… I clicked on all of them. I also added Desktop. I wonder why Desktop isn’t a default option? Oh well.

Run a full backup with GetBackup. It’ll create a folder called MyBackup under MacBackup. I chose to create a compressed backup (.tgz). Note that this full backup is partially redundant with the clone we just created with SuperDuper. Oh well. GetBackup doesn’t know about SuperDuper, and it needs its own full backup to do subsequent incrementals.

Now plug the drive into the PC. Create a folder called “PCBackup”.

Download Cobian Backup. It’s got a lot of options when setting up a task. A few that I chose: Keep Volume Shadow Copy enabled. This way, it’ll backup even if you’re working on your computer and changing the contents of folders that are being backed up. I also chose to use 7-zip compression with a 1GB split. By compressing data into 7-zip archive files, you’ll save space and, more important, greatly reduce the chance of cross-platform pathing issues.

Do a full backup of all your important folders under C:\Users\<username>. Documents, Music, Photos, etc. Even though I did a full clone of the Mac, I chose not to do this on the PC. If you want to, I’m sure there’s better software out there than Cobian to do it. You’re on your own!

So let’s recap: We now have a clone of the Mac on the Mac OS Partition. And we’ve done local backups via the USB adapter for both the Mac’s and PC’s important files.

Time to move on to wireless backup. If you read my note above, you’ve already done this: We need to setup Samba on the Pogoplug. Why? Here’s the thing about Pogoplug. It’s marketed more as a Personal Cloud than a networked drive. The Personal Cloud aspect of it is great; your hard drive is essentially browse-able from anywhere in the world. The downside: Pogoplug’s creators didn’t make it browse-able over the local network out-of-the-box. That means that if you’re at home and you use their crappy backup software, it’s sending all that traffic out over the internet just to reach the other side of the room!

So follow these instructions to SSH into the Pogoplug and install Samba on it. The instructions worked beautifully. I only ran into two quirks:

  1. I had to mount the USB to /opt in two steps: First without the -o options, then again with the -o options.
  2. I set the mount path one level higher so that any drive attached to the device is visible.

Now the drive should be accessible over the local network, either from the PC as “\\pogoplug” or on the Mac as “smb://pogoplug”. Woohoo!

Now you’re ready to setup the incremental backups. If you read my note above, you can resume the steps earlier for creating your initial incremental backups (a.k.a. “full”), but wirelessly over Samba (instead of locally over USB). That’s the beauty of both of these programs (GetBackup on the Mac, Cobian on the PC): Even though we’re changing the backup destination from the USB drive to the new networked path (okay, it’s physically the same drive, but now accessed in a different way), both programs “remember” that a full backup has already been done. In Cobian, you might have to uncheck “Tools > Options > Engine > First backup always full”. Not sure … someone suggested it, so I did, and it worked. I also checked “Run missed backups”. This ensures that scheduled backups run ASAP if the computer is asleep during the scheduled backup time.

Almost done here … So in both programs, change the backup destination to the networked path. In GetBackup, select “AutoMount” since it’s a networked drive. While you’re at it, choose a backup schedule (say, Sunday, 4pm). Note that you should choose the folder “MacBackup”, not the auto-generated “MyBackup” folder that it created within it when it did the full backup.

In Cobian, change the destination as well (to the “PCBackup” folder), and choose a backup schedule. How about Sunday, 6pm so it doesn’t conflict with the Mac backup? I’m assuming incrementals won’t take longer than 2 hours.

That’s it! We’re done! Wireless scheduled backups are now set up on the Mac and PC. The only thing I have to remember to do is run SuperDuper every once in a while to re-clone the hard drive (if I install a lot of new Applications, for example).