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Question: Can Time Machine Backup mirror 2nd Mac?

There is a MBP (primary) and MacPro (secondary) on the LAN. Both are running on Sierra 10.12.6.


The MBP is already successfully creating Time Machine backups on two different HDDs -


A- an external USB attached to the MBP (TM-A), and,


B- an internal HDD in the MacPro (TM-B).


Q1-

Will there be any problems with having the MacPro's MacintoshHD HDD periodically updating from the MBP Time Machine backup (TM-B)?


Q2-

Is there a simpler way of maintaining the MacPro as a mirror of the MBP?


Thanks.

Mac Pro, macOS Sierra (10.12.6), 5,1 / 3.33 12-core

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Answer:

Thanks Kappy.


Eric Root -

So there's CCC backups (user since 3.x) of everything, but using CCC involves migrating the entire CCC backup each time I choose to update from the MBP current backup to the MacPro.


I did try a MBP Time Machine migration into a fresh Sierra install on the MacPro, and issues were not so bad -

(Dock, monitors, ccc & TM tasks, Mouse speed, Audio I/O, Audio Midi),

so it's doable and works better the more I trim-down, cleanup the MBP content.


But I have yet to try a 2nd update since trimming down the MBP, so I do not know if this is the most efficient way to mirror two Macs.


One bonus, along with software updates, is Apps like Mail and Opera data is easily synced now.


I was concerned, mirroring 2 Macs, about software authorizations, same User/Data but with different Machine IDs, and whatever else, etc, - but no issues so far.


This setup allows for dealing with update compatibility issues on the MBP before updating the MacPro, allowing the MacPro to work without interruptions.


Thank you for your help.

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Mar 11, 2018 11:17 PM in response to Servi In response to Servi

As a rule, when the OS is upgraded you need to make a new Time Machine backup to avoid mixing old with new in the event you need to restore files. The two machines are not identical hardware. I would see no problem in migrating user files via Time Machine but not entire systems. If simply updating one machine with changes made to user files on the other, then I see no problem with that. However, Time Machine is probably not the best tool for that.

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Mar 11, 2018 11:17 PM in response to Servi In response to Servi

Try using a clone instead of Time Machine. That will give you an exact, bootable copy.


Clone - Carbon Copy Cloner (Often recommended as it has more features than some others)


Clone – Data Backup


Clone – Deja Vu


Clone - SuperDuper


Clone - Synk


Clone Software – 6 Applications Tested

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Mar 10, 2018 10:52 AM in response to Servi In response to Servi

Time Machine cannot create bootable mirrors. That can be done using Disk Utility or third-party backup/cloning software.


Regardless of how you do it, a bootable mirror must exist on a separate drive for your other backups. Of course, you will also need to update this drive when changes are made to the drive it mirrors. This could be done on any schedule you choose with most backup software.


Another possibility would be to create a backup disk by using two equally sized drives in a mirrored RAID array. Both machines could designate the array for backups. This would provide redundancy in the event one of the drives in the array fails.

Mar 10, 2018 10:52 AM

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Mar 10, 2018 1:50 PM in response to Kappy In response to Kappy

Sorry, I'm not sure I follow you Kappy.


Both MBP and MacPro had fresh installs of Sierra and were each independently updated to 10.12.6. Both are bootable. The MBP then also migrated User/Data from an El Capitan TM backup.


The question is asking about possible issues that may be, using TM backups now originating from the MBP (w/ updating User/Data), and periodically using those to migrate/update the MacPro, as a method of mirroring the the two Macs.


I've never set this up before and thought to ask.


Thanks.

Mar 10, 2018 1:50 PM

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Question marked as Helpful

Mar 11, 2018 11:17 PM in response to Servi In response to Servi

As a rule, when the OS is upgraded you need to make a new Time Machine backup to avoid mixing old with new in the event you need to restore files. The two machines are not identical hardware. I would see no problem in migrating user files via Time Machine but not entire systems. If simply updating one machine with changes made to user files on the other, then I see no problem with that. However, Time Machine is probably not the best tool for that.

Mar 11, 2018 11:17 PM

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Question marked as Helpful

Mar 11, 2018 11:17 PM in response to Servi In response to Servi

Try using a clone instead of Time Machine. That will give you an exact, bootable copy.


Clone - Carbon Copy Cloner (Often recommended as it has more features than some others)


Clone – Data Backup


Clone – Deja Vu


Clone - SuperDuper


Clone - Synk


Clone Software – 6 Applications Tested

Mar 11, 2018 11:17 PM

Reply Helpful (1)
Question marked as Solved

Mar 11, 2018 11:28 PM in response to Eric Root In response to Eric Root

Thanks Kappy.


Eric Root -

So there's CCC backups (user since 3.x) of everything, but using CCC involves migrating the entire CCC backup each time I choose to update from the MBP current backup to the MacPro.


I did try a MBP Time Machine migration into a fresh Sierra install on the MacPro, and issues were not so bad -

(Dock, monitors, ccc & TM tasks, Mouse speed, Audio I/O, Audio Midi),

so it's doable and works better the more I trim-down, cleanup the MBP content.


But I have yet to try a 2nd update since trimming down the MBP, so I do not know if this is the most efficient way to mirror two Macs.


One bonus, along with software updates, is Apps like Mail and Opera data is easily synced now.


I was concerned, mirroring 2 Macs, about software authorizations, same User/Data but with different Machine IDs, and whatever else, etc, - but no issues so far.


This setup allows for dealing with update compatibility issues on the MBP before updating the MacPro, allowing the MacPro to work without interruptions.


Thank you for your help.

Mar 11, 2018 11:28 PM

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Mar 14, 2018 6:03 PM in response to Eric Root In response to Eric Root

I will look into Super Duper, as TM and CCC are unable to incrementally "update" the 2nd Mac without fully erasing and migrating a TM Archive, or erasing and cloning a CCC backup.


The goal is to do all updates on Mac-1 and then update (incrementally over time) a "clone MacHD" on Mac-2.


I have TM on Mac-1 updating 2 drives, an attached TM USB drive, and, it also logs in and updates a 2nd TM drive over the LAN attached to Mac-2, but only if it stays permanently attached.


Problem #1-

If Mac-2 is not running during a Mac-1 TM backup, it can no longer recognize the Mac-2 TM drive logging in over the Lan, or even if it is loaded manually onto the Mac-1 desktop. The only option is to wipe the Mac-2 TM drive and start a new Archive (4+ hours).


Problem #2-

After using a USB boot drive to fresh-install 10.12 on Mac-2 and migrating from the latest Mac-1 TM Archive (2+ hours),

TM on the new Mac-2 MacHD is unable to recognize the TM backup that just created it,

therefore, in the future, it cannot go "back in time" on that TM drive, to an already updated Mac-1 TM Archive, so "updating" Mac-2 with future TM updates from Mac-1 are not possible.


CarbonCopy Cloner, same problem - CCC makes a clone of the Mac-1 MacHD, but there is no way to use that clone-file to make incremental "updates" of the Mac-2 MacHD, unless it's a total erase and clone.


Question-

Why is a newly created MacHD TM app, just created by migration from a TM Archive attached to the same Mac, why is that TM app incapable of recognizing the TM Archive that just created it?

Mar 14, 2018 6:03 PM

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Mar 16, 2018 5:45 PM in response to Eric Root In response to Eric Root

Yes, Mac-2 must be running for Mac-1 TM to find it's TM drive and backup to it.


Issue #1 - once Mac-2 TM drive is available, the Mac-1 TM App, that created it, is unable to recognize it once it is again on the LAN. WHY? It only is capable(?) of recognizing the free space on the Mac-2 TM drive, not the Archive that it created, sitting right there.


Issue #2 - once the Mac-2 MacHD is created by migrating the TM Archive from Mac-1 now on an attached drive on Mac-2, the Mac-2 TM App cannot recognized the TM Archive that just created it. WHY? If it could, I could simply ENTER TIME MACHINE and pick a date for updating the Mac2 MacHD.


The Inherit a Backup link is out-of-date. The only buttons within TM is "Back up Now", "Enter Time Machine", "Open Time Machine Preferences" - and once Preference are open - "Select a disk" and "Options" (to unselect disks).


That's it - (see) macOS Sierra: If you want a new Mac to “inherit” your backup history


There is no way for a newly migrated MacHD to see the TM Archive that just created it. You have to start all over with a new one.


QUESTION -

How can I do incremental updates on the Mac-2 MacHD with updates occurring on Mac-1 MacHD?

Mar 16, 2018 5:45 PM

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Mar 16, 2018 6:01 PM in response to Servi In response to Servi

I'm not sure I understand your question. If you want to limit what gets backed up during a backup, exclude things by clicking Options and add them there. Based on my experience, both computers can be backing up to the same drive at the same time.


For your other problems, try A4 to see if that helps.


Time Machine Troubleshooting

Mar 16, 2018 6:01 PM

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Mar 18, 2018 8:27 AM in response to dialabrain In response to dialabrain

Thanks for jumping in. Had an online Apple CHAT yesterday. Seems 10.12.6 TM sees only the available space on a desktop image of TM Logo HDD. During CHAT, TM spun for several minutes attempting to fit "new" backup on available space remains on TM-logo HDD desktop image of previously used external backup drive. I sent desktop images through CHAT to show it recognized the TM-logo HDD in the TM System Preference pane, and was listing it's capacity as limited to the free space available. Eventually it found the " Backups.bakcupdb " file and did it's job, likely only once it began to do an actual "new" backup did it see the Backups.bakcupdb and carry on.


So there is a glitch. So I will try again.


Ccc the Mac-1 MacintoshHD to the Mac-2

Start a Mac-1 TM-app Archive backup on an external Mac-2 TM HDD.

Let Mac-1 TM-app continue auto backups

Have Mac-2 TM-app spin away, trying to do a backup, until it recognizes the attached Mac-1 TM-archive Backups.bakcupdb, but stop it before it begins writing anything.

Then ENTER TIME MACHINE and attempt to - go back to the future - to the latest Mac-1 TM update.

Mar 18, 2018 8:27 AM

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Mar 18, 2018 8:36 AM in response to Servi In response to Servi

You're welcome. FWIW, there is another possible issue. Some applications only allow one installation per purchase. If you clone an app to two Macs, you are violating the spirit of their license. Let your conscious be your guide. 😎

Mar 18, 2018 8:36 AM

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Question: Can Time Machine Backup mirror 2nd Mac?