Time Machine Runs While iMac Sleeps

No, it's definitely not a green drive. If I understand correctly, a green drive adjusts its speed relative to usage. My problem is the drive spins up when there's no activity to warrant it, and I'm using it for Time Machine so I would only expect it to spin when it's backing up.

At first I thought it was being accessed remotely so I unplugged my internet, but there was no change.

Occasionally the following messages appear although not necessarily in the following order:

Dec 14 20:03:32 peters-imac com.apple.launchd[1] (com.apple.InternetSharing): Throttling respawn: Will start in 10 seconds

Dec 14 20:03:32 peters-imac InternetSharing[34601]: Internet Sharing shutting down

Dec 14 20:03:32 peters-imac com.apple.launchd[1] (com.apple.InternetSharing[34601]

I also find the following messages in the firewall log:

Dec 14 18:23:35 peters-imac Firewall[54]: krb5kdc is listening from 0.0.0.0:88 uid = 0 proto=6

What's peculiar is I have Internet Sharing shut off. Ooops, not true. While I have Airport turned off, Internet Sharing was turned on. I turned Internet Sharing off.

Obviously, I'm wondering if someone is trying to access my computer remotely, but as I said earlier, I disconnected my DSL cable and saw no change in the drive's behavior so I assume that wasn't the issue.

It appears turning off Internet Sharing (found under System Preferences-Internet & Network) has cured the problem of random startups of the external drive and failure of the drive to sleep when the iMac is put to sleep.

The only thing left is, the external drive spins constantly while the iMac is awake. If I recall, my old Time Machine drive would only spool up when a Time Machine back up was being created.

I want to try using a USB connection vs. the Firewire connection to see if that cures the problem. My logic is, when I unplug the Firewire connection the drive stops spinning even though power is applied so the issue must be some instructions coming from the Firewire port.

I'll report back. In the meantime, thanks for your help and pointing me towards using Console to diagnose the problem.

P.S. Are there any articles or books on how to use Console for troubleshooting, etc.? Hopefully articles without too much geek speak!

In my System Preferences > Energy Saver, Put hard disks to sleep when possible is unchecked. I unchecked it as part of my troubleshooting as I had read elsewhere it was recommended. It makes no difference either way.

Through some other internet sniffing, I found my way to System Preferences > Spotlight > Privacy and told Spotlight to NOT index the Time Machine Drive.

I couldn't find any Seagate or Western Digital drivers on the internal drive. I previously deleted anything I could find.

I did try using a USB connection instead of the Firewire connection. There was no change in the Time Machine's behavior while the iMac is running; it still spins continuously. It's a partial victory as the drive now goes to sleep as it should.

Thanks for all your help.

Let's claim a partial victory. Without your help, I would have been just plain defeated.

Thanks for sharing your expertise with a pedestrian user.

P.S. How do I give you the points you deserve?