Time Machine via AirDisk and CrashPlan+

I’ve been struggling with my personal backups for a while. I use a MacBook (white 13″ mid-2007, OS X 10.7.5 Lion) at home as my primary computer and have always used Time Machine. How I use Time Machine has changed over the last few years:

  • I started using Time Machine with a locally connected external portable USB Western Digital hard drive. This always worked well, but required me to remember to plug in the external HDD to run a backup.
  • I bought an AirPort Extreme Base Station (AEBS) for Christmas 2011 and connected my USB printer, my wife’s backup HDD, and my backup HDD via a powered USB hub. In doing this, I was able to share out each hard drive independently and re-seed our Time Machine backups. This worked great and automatically backed up our data hourly – no physical connections required!
  • I found a Good Friday deal this past year (2012) and bought a 1-year subscription to CrashPlan+ for 98% off (something like $2.40 for unlimited data and up to 10 computers for the year). I always liked Time Machine, but figured I should have an off-site backup too and for under $5 for the year I couldn’t pass it up.

My local wireless Time Machine backup combined with my offsite wireless CrashPlan backup seemed like the ultimate solution, and it was for about 10 days.

Starting about a week before Christmas, my Time Machine backup stopped working. After much troubleshooting, I realized that I couldn’t even connect to the AirDisk shares on my AEBS. Rebooting the base station fixed this problem temporarily. Reformatting my HDD and re-seeding my backup only worked as long as it took to finish the initial backup, then continued to fail. Again, I couldn’t connect to the AirDisk shares without rebooting the base station. I did more research and tested more theories, but Time Machine would never continue to run for long. I finally shut off Time Machine and left it off for a few days. During this time, I could connect to the AirDisk shares anytime I tried. Once enabling Time Machine again, it ran for a few backups, then failed again.

Eventually it dawned on me that Time Machine stopped working around the time I started using CrashPlan+. I disabled CrashPlan+ and Time Machine has been running successfully for about 4 days now, no hiccups whatsoever!

It seems that much like having more than 1 antivirus solution running on the same system isn’t good/recommended, multiple backup solutions running on the same system also doesn’t appear to be the best idea. Unfortunate too, CrashPlan+ has an article about how their product compliments Time Machine. Personally, I will rely more on Time Machine since I have it set to backup everything on my hard drive. I only used CrashPlan+ to backup certain areas of my hard drive that I wanted offsite. So, If i can keep Time Machine working I’ll be happy.

Some additional ideas I wrote down for troubleshooting that I haven’t gotten to try yet include:

  1. Wipe AEBS settings/configuration – I already downgraded firmware to 7.6 and then re-applied 7.6.1 when the downgrade didn’t work.
  2. Test wireless Time Machine backup without USB hub and enable CrashPlan+ again.
  3. Test directly connecting my portable HDD to my laptop and running the Time Machine backup again with CrashPlan+ enabled.

If I ever find out exactly why the two technologies don’t work together or if I ever discover a workaround, I’ll post again. One theory I had was that there could be an issue if they’re trying to backup the same file at the same time. I couldn’t find a way to schedule either (for example, running them every other hour), though I’ll admit I didn’t look too hard yet.

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