I have a 2TB time Capsule wirelessly attached to my iMac (~90GB used, 1TB disk). Once I have about 3 months of backups, Time Machines says I need to start a new backup. When it does that, all data in the "current" backup is lost. Time Capsule doesn't appear to be full. I can't find a setting to save existing backups before creating a new one. Is there one?
iMac, macOS High Sierra (10.13.3), no other iMac problems noted
Time Machine will automatically delete backups and start a new backup if it detects that the backup file has become corrupted......which is an issue that countless numbers of users have been experiencing. A message like the one that you see below will appear when/if the backup file becomes corrupted.
Unfortunately, there is not much that you can do to prevent this from happening again, so you might want to consider using a USB drive connected directly to your Mac for Time Machine backups as well as a Time Capsule. Using a USB drive is a far more reliable way to back up your Mac.
The issue is with Time Machine backing up to a "network" drive, like a Time Capsule or other NAS. There are no issues with Time Machine backing up to a "local" disk, like a USB hard drive connected directly to a Mac.
The corruption issue has attracted the attention of major publications....see the link below for an example....but unfortunately Apple has not yet provided a fix for the problem.
It is a Time Machine software problem, not a Time Capsule hardware problem. The issue was known as far back as Leopard and Snow Leopard, but it is much worse with Sierra and High Sierra.
I have used another application......Carbon Copy Cloner.....to back up the Macs here to a Time Capsule for years, with flawless results.
During that same time, the dreaded message that you see above has appeared on average, about twice a year for each Mac backing up using Time Machine to a Time Capsule, but at irregular intervals.
Macs that have been backing up using Time Machine to a USB drive connected directly to the Mac have been fine for years. No issues at all.
As far as Carbon Copy Cloner is concerned, I have no interest in the product other than that as a customer.
Thanks, Bob. I guess the corruption could be either with the iMac drive or the Time Capsule drive, or the Time Machine backup software. If it's one of the drives, can the bad sectors be "mapped out"? If it's a common problem in the Time Machine software, is Apple working on a fix? If it's the wireless connection, should I consider a wired (USB?) connection from my Time Capsule to my iMac?
Seems a shame to not be able to use the Time Capsule via my wireless network.
Thanks, Bob. I hate loosing data, just like everyone else, but it's doubly disappointing to be told "no biggie". There are lots and lots of things about Apple to love, and I do, but this is not one of them. Makes you wish there was a "kickstarter" project dedicated to solving this problem, or a way to get Apple to resolve it for us.
Thanks again, both for the answer, and for answering so promptly.
Time Machine not using all of Time Capsule
