Help Deciphering Time Machine Message

[curiousjo]

I have a Macbook Air that is connected wirelessly to an HDD and run a TM backup multiple times per day. It’s been chugging away just fine for a couple of years. Recently, however, I got a message: Time Machine completed a verification of your backups to “XX”. To improve reliability, Time Machine must create a new backup for you. Click Start New Backup to create a new backup. This could take several hours. Click Back Up Later to be reminded tomorrow. Time Machine won’t perform backups during this time. I’m running out of external drives and had hoped that this one would last for a while longer.

Does anyone know what would cause this type of message to occur? Does it mean that the HDD has some kind of corruption? If I click "Start New Backup, will the history be erased but the latest version of the backup be intact, or does everything get wiped out? Thanks for any insights you may have.

 

[Bigwaff]

Does anyone know what would cause this type of message to occur? Does it mean that the HDD has some kind of corruption? If I click "Start New Backup, will the history be erased but the latest version of the backup be intact, or does everything get wiped out?

It could be various things that corrupt your network TM sparse bundle image. Once the sparse bundle is corrupted, it’s unlikely it is worth saving. In the end, you’re better off starting a new backup. When you say “wirelessly to an HDD”, can you describe specifically the set up how your HDD is shared over the network. Is the drive attached to a router? Another computer? Does the drive use external power or is it bus powered? What version of macOS is your TM client Mac? These details may help understanding why and help avoiding again in future.

 

[Fishrrman]

OP:

You have CarbonCopyCloner as well?

My opinionated advice:
Take that cryptic time machine message as an indication that you ought to stop using tm and keep right on going with CCC instead.

Things will go better that way.

My opinion only.
Others will disagree.
Some will disagree vehemently...

 

[CaptTee]

OP:

You have CarbonCopyCloner as well?

My opinionated advice:
Take that cryptic time machine message as an indication that you ought to stop using tm and keep right on going with CCC instead.

Things will go better that way.

My opinion only.
Others will disagree.
Some will disagree vehemently...

I don't disagree vehemently but wonder, if something is important, why don't you have 3 clones and 3 Time Machine backups?

 

[Fishrrman]

"if something is important, why don't you have 3 clones"

I DO have 3 cloned backups:
- One sitting next to the Mac (not connected to Mac and switched off)
- Second in waterproof and fire-resistant box in the basement
- Third in the car

They're not all updated at once, so the slightly-older ones have earlier "versions" of changed files.

 

[CaptTee]

"if something is important, why don't you have 3 clones"

I DO have 3 cloned backups:
- One sitting next to the Mac (not connected to Mac and switched off)
- Second in waterproof and fire-resistant box in the basement
- Third in the car

They're not all updated at once, so the slightly-older ones have earlier "versions" of changed files.

Back before the turn of the century, I lost a file once, so my 6 backups beats your 3 backups. You just aren't paranoid enough if you think 3 clones is enough! LOL!

 

[!!!]

connected wirelessly

Does it mean that the HDD has some kind of corruption?

It means the sparsebundle that TM backs up to is corrupted. It's possible that this is due to a bad HDD, but far more likely just another issue with network-based backups. Any kind of communication failure or lag can cause this, and it only gets worse when you use Wi-Fi.

My advice is to connect the HDD directly to your Mac and back up that way. You do lose some of the convenience, but if you weren't sitting there with your laptop next to your router while backing up, you weren't going to get reliable backups anyways.

 

[MayflyMaven]

I have a Macbook Air that is connected wirelessly to an HDD

So you're essentially backing up to NAS storage (the backup disk isn't directly connected to your Mac), in which case the Time Machine backup is on a disk image.

I got a message: Time Machine completed a verification of your backups to “XX”. To improve reliability, Time Machine must create a new backup for you. Click Start New Backup to create a new backup.

This error is usually presented when the disk image is corrupted and can't be mounted. This is a long-standing Achilles Heel of Time Machine when making a backup on a NAS – Time Machine places the whole backup into that single-point-of-failure disk image file, and that disk image device is pretty fragile (based on the number of times this error message pops up on the Internet).