"Time Machine" Data Management Changes

[3282868]

Anyone notice differences in "Time Machine" management of data?

I have a 3TB SATA II HDD in my "Mac Pro" for "Time Machine" backups. Since my Mac Pro has 6+ TB's of working data, I am very selective on what data to backup. Usually I wipe it clean ~6 months and start fresh as data management wasn't very reliable. On the current 10.9 DP, I noticed it handled backups much better; with less than 500GB's of storage space, it automatically purged enough data allowing 1TB of space. This has never happened for me before, usually it stops backups with error messages.

Does anyone know how it determines what data to purge, what to keep, and how it collates data? Thanks!

 

[maflynn]

Is it purging or no backing up all your data?

 

[chabig]

Does anyone know how it determines what data to purge, what to keep, and how it collates data? Thanks!

Time Machine keeps hourly backups for the past 24 hours, daily backups for the past month, and weekly backups until your backup drive is full. Time Machine intelligently deletes the oldest backups to make room for newer ones (and will alert you if the "Notify after old backups are deleted" option is selected in Time Machine preferences).

This is straight from https://support.apple.com/kb/HT1427

 

[3282868]

Time Machine keeps hourly backups for the past 24 hours, daily backups for the past month, and weekly backups until your backup drive is full. Time Machine intelligently deletes the oldest backups to make room for newer ones (and will alert you if the "Notify after old backups are deleted" option is selected in Time Machine preferences).

This is straight from https://support.apple.com/kb/HT1427

Right, I understand that aspect (not a beginner here ). My question is, how does it determine what data to purge? By date, type, size, etc?

Is it purging or no backing up all your data?

Since introduction years back, most often it would cease backups once the volume was full. I always select what to exclude, usually folders/volumes that are not critical and would constantly have a plethora of data come and go (desktop, downloads folder, working/scratch directories). I would include media/iTunes, finished projects and/or directories automated to save work at various times instead of large hourly film/CAD project backups, etc. Normally a clean, initial backup consists of 1.84 TB's on a 3 TB "Time Machine" volume and accumulates until roughly full (~6 mo's time). This is the first time it hasn't stopped backing up once full, and began deleting files (essentially what it should have done initially). I've never bothered to research the exact specifics as to how it determines what data to purge until, well, now that it seems to be working (and this is over the years with clean OS installs on numerous Mac's).

Thanks guys!

 

[maflynn]

I never had an issue that TM would suddenly stop backing up because the volume is full. As chabig stated, it would delete old backups before undertaking the new backup.

 

[Inconsequential]

It deletes whole backups until there is enough space to complete a backup.

So if it needs 500GB space it will delete the oldest backups until 500GB is free.

 

[jhfenton]

I had that problem twice under ML, but not yet under Mavericks.

Time Machine would calculate an inaccurate backup size needed, then keep increasing the "target" as it backed up. When the backup volume filled, it would result in an error, as Time Machine thought it had enough room when it purged, but then it would run out in the middle. Usually repairing permissions and fixing errors on the backup volume would fix the problem.

 

[3282868]

It deletes whole backups until there is enough space to complete a backup.

So if it needs 500GB space it will delete the oldest backups until 500GB is free.

That makes sense. Backups are removed by date and size necessary for new data, removed, and the process continues.

I definitely need to get a larger backup volume. Might have to play around with spreading "Time Machine" across multiple volumes, or invest in a 60TB Seagate HAMR drive .

What is the largest size 3.5" SATA? 3TB? 4TB? HAMR drive range from 6-60TB, current Mac Pro's only recognize 8TB's total, no? Thanks again!

Usually repairing permissions and fixing errors on the backup volume would fix the problem.

Didn't realize permissions might be a factor on "Time Machine" volumes, thanks for the tip.

 

[Inconsequential]

Current mac pros accept any size disk.

 

[3282868]

Current mac pros accept any size disk.

Embarrassed to admit, I thought each SATA II bay maxed out at 4TB per. Been using PowerMac's and Mac Pro's for a looooong time. You'd think I know my current gen5,1 (for now) could handle a large volume.