Operating systems

I was pretty amazed to notice that my Mac actually wakes up for the sole purpose of running a scheduled backup and goes back to sleep. Oh, but why?

Going to web with the issue helped, I found Apple support community discussion with topic "time machine wake up unwanted". I don't think my pre 10.9 did that. Anyway I can confirm that 10.9 does this rather stupid thing.

Luckily the discussion thread also offers the fix: "Time Machine won't wake up a Mac, unless another Mac is backing-up to a shared drive on it via your network, and the Wake for network access box is checked in System Preferences > Energy Saver". Definitely something for me to try.

It helped! I can confirm, that there are no backups for the time my Mac was asleep. Pretty soon I woke it up, it started a TM-backup and completed it.

Thanks Pondini in Florida, USA!

Lot of my Windows 7 testing is done in a virtual installation. I run it under KVM and aim for small disc footprint, I have a number of other boxes there too. One day I came to realize that my Windows 7 installation is running out of disc space. That would be strange, I literally have nothing installed in it and it still manages to eat up 30 GiB of space.

There is Microsoft KB Article ID: 2795190 How to address disk space issues that are caused by a large Windows component store (WinSxS) directory explaining this behavior.

The fix is to use Deployment Image Servicing and Management tool DISM. Run something like this as administrator will help:

C:\Windows\System32\Dism.exe /online /Cleanup-Image /SpSuperseded

it will say something like "Removing backup files created during service pack installation". It will remove more than 4 GiB of space. Rest of the garbage will stay on the drive as they originate from regular windows updates.