Updated* - Time Machine - Multiple disks/ location feature available now

gspannu said:

Updated: The screenshot was removed in my previous post by mistake. Apologies

Mountain Lion finally gets the long awaited feature to use multiple disks for Time Machine Backups.

Now, when you select a different disk, you get an option to 'Add Backup Disk' - rather than just change the disk.

Adding backup disk will auto use the disks depending on availability as per the accompanying text.

Welcome feature, see screenshot for more details…

Click to expand...

Have you noticed any strange Time Machine behaviour like it complaining the disk is missing when it isn't?

When you have multiple disks being used for Time Machine backups, does it retain one daily backup per disk?

I know the preview of Mountain Lion hasn't been out long enough yet to know what it does after a month.

Does this mean I can have different exclusions for different disks? I have one big disk and one small disk, and I can't fit everything on the small one (I want to have a full backup, and a secondary backup of only the most important stuff).

Right now, if I plug in one disk after unplugging the other one, I have to set up exclusions again to exclude dozens of folders except the one I want to back up...

Does anyone know if you can choose disks based on the user in 10.8 server? Or does it just treat it as a span of disks? Either way, it's an improvement.

Does this mean that the entire backup is on both disks (i.e. when you plug in a new disk, the backup gets 100% copied over to the new one, and any new changes are added to both disks) or it's divided and spread out over both? An advantage to the first option would be, of course, to have a redundant backup, but an advantage of the second would be that Time Machine could keep older backups without having to delete them. Not sure which option I like more...

The "TM will rotate backups based on disk availability" doesn't really clear that up for me, but maybe I'm missing something. It could mean that the entire backup is copied to both disks whenever they're available, or it could also mean that once a file is backed up to one disk, that's it, it doesn't get copied over to the other. Anyone know?

To me it sounds like it might actually alternate between backing up to one disk, then the other, unless of course only one disk is available at the time.

So if you are ever potentially in a situation where both disks may be attached at once, then it would switch between the two, so no disk is more than one backup behind.

This would make sense if the point is so you could have a laptop with a backup drive at work and one at home, or one at each home if you have a holiday home or working apartment or whatever. So you don't have to carry disks around.

I think that for anything more serious you'd still need heavier duty backup solutions.

My best guess about what "TM will rotate backups based on disk availability" means is: (Based on 2 disks)

• 1 AM: Backup to Disk1 everything that was changed since the last backup to Disk1
• 2 AM: Backup to Disk2 everything that was changed since the last backup to Disk2
• 3 AM: Backup to Disk1 everything that was changed since the last backup to Disk1
• 4 AM: Backup to Disk2 everything that was changed since the last backup to Disk2
• and so on...

If you have 3 disks, add that in to the rotation.

Based on my interpretation, there is one exclusion list and no per backup disk settings. Where this helps is disks do fail. And although you don't expect more than one disk to fail at a time, stuff happens. And in the simple case of one backup disk failing, you still have access to backups from the other disk(s).

I think TIme Machine needs to evolve to where it's good for business use. One of the short falls I see is I should have the option to save hourly backups for up to at least 2 weeks and daily backups up to somewhere between 1 and 6 months depending on the business.

Heck for personal use, I wouldn't mind hourly backups being saved for about 3 days.

Does anyone know what happens when one of the backup discs is larger than the other? I'm looking to plug a 4 tb external into my 1 tb Time Capsule. Up until now, I've been excluding backups of my 2 tb media drive that's plugged into my computer, due to the Time Machine's size, and just cloning it once a week to the 4 tb. If it will be possible for me to back up my computer and my 2 tb external to my Time Capsule and 4 tb external, I'd love to know!

Need exclusion list by backup drive

Bummer, this sounded so promising. I need exclusion list per backup drive.

When I'm mobile, I back up to a small drive. When I'm in my office and plug into a bank of external drives, I want to backup more data to a larger backup drive. Today I have to switch the backup drive manually.

now if only apple added time machine backups to iCloud

Now restore the ability for iPhoto backups as before and I'll be set. I'm disappointed Apple removed the availability to restore individual photo's, events, etc in iPhoto with "Time Machine", instead forcing a full restore of the library file should you accidentally delete/empty trash of pics you need. It worked just like all their others apps; open iPhoto, click on "Time Machine", iPhoto open in "Time Machine", restore photo's, etc.

No longer...

This is a great new feature. I think I'm more excited about this than any of the other new Mountain Lion features.

I've just updated to Mountain Lion today and am already using this feature. Now I can backup using Time Machine automatically to multiple NAS units if I want to!

Exclusions to vary between discs?

dmelgar said:

Bummer, this sounded so promising. I need exclusion list per backup drive.

When I'm mobile, I back up to a small drive. When I'm in my office and plug into a bank of external drives, I want to backup more data to a larger backup drive. Today I have to switch the backup drive manually.

Click to expand...

I really need this feature as well as I would prefer to backup only work files at work (no need for them at home) and other files I'd like to not have at work (personal pictures, videos, etc.). Is there a way perhaps to see exclusions listed in a file somewhere in the hierarchy of OSX or perhaps on the backup itself? Thanks.

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Can somebody with Mountain Lion confirm if this file:
/Library/Preferences/com.apple.TimeMachine.plist
has multiple drives listed and if you can specify specific files for each drive in that manner? Thanks to anyone who looks and/or tries this out.

Yay!

...oh, right, Apple doesn't support Mountain Lion on my mid-2006 Mac Pro. WTF?

Yeah, yeah, I know there is a "workaround" that involves replacing graphics cards, installing Chameleon, etc. It's just stupid that this requires a workaround.

monyker said:

...oh, right, Apple doesn't support Mountain Lion on my mid-2006 Mac Pro. WTF?

Yeah, yeah, I know there is a "workaround" that involves replacing graphics cards, installing Chameleon, etc. It's just stupid that this requires a workaround.

Click to expand...

Early 2008 Mac Pro is the oldest Mac Pro which is supported.

I currently have two drives connected; a Time Capsule and a Synology NAS both via wired ethernet.

To my surprise the dual disk backup rotation is pretty stupid. Time Machine will only backup to the FIRST available drive unless it is disconnected in which case it will backup to the second one. The only exception being the first backup will be done in the newly added drive right after you add it.

I've just noticed this after a week of having both drives set up. I now see that the Time Capsule drive has all my hourly backups but the second drive has "Only backup: <last week's date>". No matter if I force the backup, every time it attempts to do it in the Time Capsule.

This sucks since the Time Capsule will be always available and I have no way of unmounting it to force the secondary drive backup.

Is it me or is this a pretty ridiculous backup strategy? It seems to me that round-robin would be much more intelligent.

My 2cts.