Time Machine Gets Stuck In "Calculating Changes"
I have a 2010 15" 2.53 GHz i5 MacBook Pro, running 10.6.5. My time machine back-up volume is a 1TB Fantom GreenDrive Quad ( http://fantomdrives.com/products/greendrive-quad.htm) connected via FireWire 800. My drive is formatted and partitioned correctly (Mac OS Journaled, GUID Partition Table).
The first time it happened, my troubleshooting research led me to determine that the safest way to "unstick" TM was to open Activity Monitor and force quit the "backupd" process. This ended the TM process, but I was still unable to unmount the TM volume or restart my MacBook without having to do a hard shutdown. I would, then, boot up, reconnect and mount the TM volume, and the backups would resume as normal. I verified, both, my internal drive and the TM volume with disk utility and found no issues.
The second time it happened, I decided to do a hard reset of TM which, essentially, entails trashing the TM preference file and setting up TM again from scratch. At this point, I thought I was in the clear.
The third time it happened, I researched the issue a bit further. It started a back up and then it hang on "calculating changes". I payed attention to the console logs at the time this occurred and saw the following:
1/17/11 11:01:58 PM kernel IOSCSIPeripheralDeviceType00::setPowerState(0x13e9db00, 1 -> 4) timed out after 100171 ms
1/17/11 11:06:05 PM kernel IOSCSIPeripheralDeviceType00::setPowerState(0x13e9db00, 4 -> 3) timed out after 100116 ms
1/17/11 11:11:05 PM kernel IOSCSIPeripheralDeviceType00::setPowerState(0x13e9db00, 3 -> 2) timed out after 100120 ms
1/17/11 11:13:05 PM kernel IOSCSIPeripheralDeviceType00::setPowerState(0x13e9db00, 2 -> 4) timed out after 100119 ms
1/17/11 11:16:25 PM kernel IOSCSIPeripheralDeviceType00::setPowerState(0x13e9db00, 4 -> 3) timed out after 100117 ms
I'm not an expert at reading these things, but more online digging led me to believe that my issue has something to do with the Fantom Drive's own power saver mode. It seems that, periodically, TM may start a back-up and have difficulty waking the drive from it's sleep state (can anyone verify if I'm off the mark, here?).
From my research, it seems like the fix to this issue is to deselect the "Put Hard Disk(s) To Sleep When Possible" option in the Energy Saver preferences (this is also the suggestion offered in the manual for the drive itself). I haven't yet concluded whether or not this has resolved the issue. I can only wait and see.
Can anyone else tell me if they've had this sort of issue and how they have, ultimately, solved it?
Is deselecting "Put Hard Disk(s) To Sleep When Possible" detrimental to performance in any way? It's not as if the drive never sleeps. As per my routine, I, manually, put my computer to sleep twice a day (before I go to bed, and before I leave for work in the morning). When I do, both the computer and the drive spin down.
Sorry for being long winded. I'm annoyed that this problem keeps occurring and want to put a stop to it.
Thanks.
MacBook Pro 15.4 inch 2.53 GHz Intel Core i5, Mac OS X (10.6.5)