I have been testing the Time Machine backup on my MacBook Pro 15" Mid 2010 - Mac OS X !0.7.2 (Lion) - to my MyBook Live 3TB (02.02.02-020 Firmware) drive for about 3 weeks. Typically I back up all of my Macs to an Apple Time Capsule.
What I have consistently observed in my 3 weeks of testing the Time Machine backup with the MyBook Live is that Time Machine will backup correctly to the MyBook live if I specifically tell it to “backup now” - or if an hour passes and the Time Machine invokes an hourly backup - which is what it supposed to do.
However, if the MacBook Pro goes to sleep. Upon waking the Mac - what “should” happen - but does “not” happen is the Time Machine should start a backup operation within 30 to 60 seconds of waking from sleep. This is how Time Machine behaves when it is backing up to the Apple Time Capsule - and this is consistent across all 3 of my Macs.
With the MyBook Live set as the backup drive for Time Machine - upon the Mac waking from sleep (regardless of how long it has been sleeping) - the Time Machine backup does not start until 20 to 40 minutes after the Mac has woken up. Often the wait is longer - and at times it will even skip the backup at the next stated time.
The problem this creates is - (for example) the Mac is running on battery and has a very short interval before it will go to sleep - so with the Time Machine not starting a backup within the first few minutes after wake - there is the likeliness that the Mac will sleep again before Time Machine runs the backup - effectively never backing even over a period of many hours.
When the backup runs - there are no errors - everything appear to run smoothly. I am basically questioning why the Time Machine Backup is exhibits a different operational behavior when backing up to the MyBook Live - vs. - backing up to the Apple Time Capsule.
What I have not tested yet is whether this is happening on my other Macs with the MyBook Live. I will post the results of testing with a different Mac later this weekend.
Also I should not - that immediately upon returning the Mac to backing up via the Time Capsule - the normal post-sleep behavior resumed.
Why is Time Machine treating the Time Capsule any different than the MyBook Live?
