Sunday, June 12, 2011

Spotlight will index your Time Machine backup disk

I caught my MacBook's fan noise, so i looked to see what was sucking CPU.

It wasn't, surprisingly, Flash. The MacBook was trying to index the backup drive attached to my Time Capsule upstairs, even as it did its routine Time Machine backup to the remote image.

I'd seen that on other machines, so I knew the fix. I added the remote mounted backup drive to my Spotlight Preferences Privacy tab. The fan spun down a few minutes later.

It's a surprising behavior. Does Spotlight also try to index a TM backup on a physically attached drive? Obviously this kind of indexing is pointless, just a waste of bandwidth, storage, CPU and power. I'm surprised it's not been fixed.

Update 6/22/11: There are odd consequences with doing this, esp. in 10.5. This 2008 discussion is interesting -- TUAW Tip: exclude your Time Machine disk from Spotlight indexing and 10.5: Spotlight and the Time Machine disk - Mac OS X Hints


Martin said...

It is probably a feature, not a bug because it allows searching of backups.

Since the Time Machine is already very slow and I had never any reason to search my backup, I added my Time Machine drive to Spotlight's 'privacy' list a long time ago. In addition, Mac OS X does not get confused on where to start applications and to get data from …

JGF said...

I see what you mean Martin. So not a bug, but still most of us will prefer to use the privacy feature.

I'd done that on my other machine a long time ago, but somehow missed the laptop -- or lost the setting when going form 10.5 to 10.6.

Doing indexing of a 200GB backup over WiFi is pretty demanding and slow ...