I've placed my Photos Library on an externally mounted SSD. When I use Time Machine to backup the computer Time Machine will backup the entire Photos Library instead of just what's been added. Is there any solution to avoid this behavior?
Mac Studio, macOS 15.7
I've solved my issue. I excluded the Pictures folder residing on the external fast SSD from Time Machine backup. And have tasked the backup program Retrospect with backing up only that Pictures folder to a separate external hard drive. Now Time Machine no longer re-backs up that entire 1.59TB folder. Retrospect incrementally backs up the Pictures folder taking a small fraction of the time and space Time Machine was taking. I'm happy again.
I've solved my issue. I excluded the Pictures folder residing on the external fast SSD from Time Machine backup. And have tasked the backup program Retrospect with backing up only that Pictures folder to a separate external hard drive. Now Time Machine no longer re-backs up that entire 1.59TB folder. Retrospect incrementally backs up the Pictures folder taking a small fraction of the time and space Time Machine was taking. I'm happy again.
Ken Shimabukuro wrote:
I excluded the Pictures folder residing on the external fast SSD from Time Machine backup.
What format is the external drive? It should be APFS or MacOS Extended, non-Mac formats like exFAT are not supported for Photos libraries.
Also notice that some backup systems might repeatedly backup files with file creation or modification dates older than 1970.
First, try using Black Magic Disk Speed Test from the app store to see if that SSD doing OK. My SSDs usually come in at a bit more than 700 MB/s.
You can also use Disk Utility to do First Aide to see if it sees anything.
Let us know…
I tried an experiment today. I ejected my SSD containing my Photos Library and initiated a Time Machine backup. It backed up nomrally within 2 minutes. I remounted that SSD and Time Machine has been backing up for the past 8 hours and still says 2 hours remaining. But Time Machine has said 2 hours remaining for the past 5 hours. So how do I backup my Photos Library if having it on an external SSD isn't allowing for normal Time Machine backups?
Black Magic - Disk Speed Test results WRITE: 2318.5MB/s, READ: 2783.5MB/s for my external Photos Library SSD. Disk Utility's First Aid reports volumes appear to be ok File system check exit code is 0 (no errors were found) on both the backup destination volume and the SSD my Photos Library is held on.
So, the issue isn't speed of SSD that I keep the Photos Library on, or the write speed of the Time Machine backup drive, it's that Time Machine is re-backing up almost all or all of the drive the Photos Library is kept on.
Ken Shimabukuro wrote: …So, the issue isn't speed of SSD
That's true.
My System Library is not on an external drive, so I'm not sure what's going on. Other than the time it takes, I'm not sure how you know that TM is making a new copy of the Library each time-- in the Time Machine Data, there's no indication of
of the fraction of the package that was in the recent update. Each file, folder, or package just shows the resulting total every time.
What do you see?
What I was asking was, how do you know "that TM is making a new copy of the Library each time," rather than the time being due to some other problem.
My picture was to illustrate that what we can see looks the same whether Time Machine has just made a new copy of the entire Library, or it has just made an incremental adjustment.
What are you asking, exactly. Could you word your question differently?
Using Time Machine to backup a Mac with Photos Library on external SSD frequently re-backs up everything
