Nothing has improved with this issue. When the TC got to 100 GBytes I erased it and started over to make an initial complete backup and sure enough two days later while working it said "3 GB required..." and an hour later it had copied ~20 GBytes. It does it when I'm working and when it's doing nothing (overnight minimal apps running). Some clues or things to check to understand or debug it would be helpful because it eats a TC quickly with worthless backups of 20-50 GBytes.
These may already have been suggested to you.
Anything that is changing slightly eg iphoto may require a full library backup.. same with itunes.. the way the library works now is a single flat database.. it is really a terrible system.
Any icloud backup that stores locally before uploading..
But the best idea is the A2 to get the actual info.. the log misses that info.
Thanks. I haven't used iPhoto or iCloud for backups. What I think maybe happening is the daily(?) backup doing the whole previous day's of changes. What I need to find is where the com.apple.backupd logs are written to check the available space to see if the jumps are consistent for the same time every day for the daily backup, but they haven't seemed in the past.
What's odd is that the backup of a number or large changes doesn't seem out of the ordinary of the rest of the backups except taking maybe 5-10 minutes instead of 3-5 minutes. I've cleared both spotlight files and did a disk utility on the sparsebundle, which showed no errors and didn't effect the scheduled backup.
Anyway, thanks for the help. I'll keep watching things to learn more.
I found out how to use the Console window to search backward for the com.apple.backupd entries going back days to find where any anamolous jumps in the space taken by the backup. It doesn't explain the sudden jumps for an hourly backup to take 25-50 GBytes since the're random and not every day for any daily backup. Just weird.
Does anyone know how to see what the backup is doing or what it's backing up? For the fourth time in 10 days it wrote the lines for the latest example:
Found 99 files (2.2 MB) needing backup
2.88 GB required (including padding), 533 GB avaiilable
And then it went and ran for two hours to backup up over 50 GBytes of what I don't know.
This is what it does every time and it's not consistent when it does it except it's every 3-4 days. I realize it's not really important since it deletes space to do a backup when the HD runs out of space, but doing these backups and deleting the space when it's full interfers with the disk usage and network resources with other applications running. It doesn't matter if I turn the backup off because it resumes where it was when I turn it back on.