I keep a Time Machine backup on my MBL. However, I don’t use MBL as my main TM backup drive, preferring instead to use a separate USB HD for TM. Having made a TM backup to MBL what I tend to do then is just do a periodic backup to MBL to keep it current i.e… Incremental about once a fortnight. This is where my problems start. I have noticed that any subsequent incremental to MBL are slower and more erratic with each attempt. I was trying to do one last night and it took 45 minutes to transfer 114mb - ridiculous. Despite a reboot things didn’t improve and I ended up doing what I have had to do in the past i.e… deleting the full backup and starting again. Anyone any ideas why this should be? I have the very latest firmware on MBL i.e. the one that has currently been withdrawn.
If you transfer a file manually, do you get the same slow transfer rate? Also check the link below for some recommendations on how to improve the transfer speed.
File transfer speeds remain speedy and unaffacted. I have also noticed that when I delete one of these troublesome TM backups and start again, providing I leave MBL as the primary backup for TM then the backups continue without incident. It appears to me the very act of breaking the connection for MBL as primary TM backup is where the problem lies. As said before I use a WD USB as the primary TM backup target and only revert back to MBL for the odd incremental TM backup in order to keep it current. My intention being to use the MBL TM backup as insurance should anything happen to the USB drive.