Time Machine Backup Precautions

Very wise.. asking beforehand.

The best way to make a backup of your existing computer is to buy a USB hard disk.. they are not expensive at all.. download Carbon Copy Cloner.. it is free trial for the first month.. and make a bootable image of your computer on the USB drive. Ensure it works by booting from it.

You now have your whole computer hard disk imaged onto a drive .. and that drive is a perfect and exact image of what is on your laptop.

When you then upgrade to Mavericks.. and if it does mess up your Time Machine backup .. then you have all your files perfectly safe and can in fact boot the computer back to Mountain Lion exactly as it was before Mavericks reared it head.

I would recommend once you upgrade the computer.. rename it.. first thing. or even before you do the upgrade, so hopefully you can force it to do a new and completely separate Time Machine backup.

It is also possible to archive off the existing Time Machine backup on the TC. The archive function was restored to the airport utility recently, you might need to update your Mountain Lion or at least the utility to use it. But IMHO the clone is a lot better.. it is after all exact.

You cannot boot from the TC.. so no, the TC is not a suitable target.. you can backup to the TC but that is entirely different to creating a bootable backup. You must use an external drive.. the cheapest is USB but you can use any disk that you can plug into your computer.

By "force it to make a new backup" do you mean that I will need to make two backups for my computer or do you mean make a new backup after installing Mavericks so the TC doesn't mix the backups with different OSs?

Can I access my old backup with Mavericks or will it be corrupted? A review mentioned mounting the backup as read-only. How do I do this?

I mean that you do not want to load Mavericks onto the computer and the first thing it does is destroy your existing backup which it can do.. so rename the computer as a way of trying to prevent that from happening.

With a new name.. Mavericks should start a whole new backup.. so you will then have two backups the old OS and the new upgraded OS.

You still should be able to access your old backups from Time Machine if you don't destroy them.

Mount your backups as read only.. hmmm I am not sure.. as long as you turn Time Machine off, before you even load Mavericks it should be ok.. I do not understand the comment.

Do not try and restore a computer from TM.. it is simply too hard.

And you want guarantees .. I cannot give them.. if you mix backups on the one device there is no way I can give iron clad guarantee that it will work with 100% safety and no corruption.

Buy a USB drive.. plug it into the computer and make an image. You can use CCC.. you can use superduper and you can even use disk utility.. but I am not sure if you can make it bootable with the later.

By using an image then booting from it.. you have a 100% known guaranteed backup... if you don't like Mavericks you can then simply boot from the USB and use the same software to target the USB back to the internal disk.. it is done fast, a fraction of the time it takes TM.. and done without lossing track of iphoto or itunes or your emails disappearing.. or half the issues that TM has.

The cost of a USB drive to manage this is very small cf the pain without it.

Arc676 wrote:

Does changing the computer name or turning off TM in System Preferences actually affect the files on the backup disk? I didn't do any sort of backup when I upgraded to 10.8, which wasn't very safe, but I had no problems whatsoever. My plan is to change my computer name, turn off TM, then disconnect my computer completely from my TC, then install the new OS. I have little doubts I will like Mavericks.

I just wanted to know that nothing will happen to the backup itself when I turn off TM or change my computer name.

If you change the computer name it may or may not result in the TM being able to find the backups.. It seems to not be consistent.. Test it and find out before you upgrade.

Certainly if you do what many people have done in upgrading to Mavericks it has resulted in a corrupted backup.. what happened I do not know. Turn off your Time Capsule and then it cannot corrupt the backup.

If you want to restore the computer after you upgrade it is very difficult from Time Machine.. if you have predetermined you like Mavericks then it won't matter.

If you do want to restore I already explained how to do it. In my first post.. download CCC and make a clone of the existing hard disk.

What exactly does it mean to have a "corrupted" backup? Does it just mean that the hard disk in the TC has lost data?

You cannot restore older backups or you cannot restore at all.

You will not be able to restore to a point before you tried to upgrade to Mavericks.

The TC has not lost data.. you simply cannot get it back. Hence corrupted.

What are the most evident signs of backup corruption?

You cannot restore.

You cannot tell from looking.. even a verify can pass.. but still cannot restore. Test a backup using verify.

See Pondini A5.

http://pondini.org/TM/Troubleshooting.html

But the true test is do a full restore.. only then will you KNOW the backup is 100% good.. and with TM you need to make sure all your files and libraries are accessible because they are not always restored.

How can I prevent corruption before I update (I plan on updating in about a month)?

This is not the problem.. the problem occurs when you upgrade OS and it overwrites the backup.

The best solution is to take a disk image today.. and boot from it.. buy CCC.. buy a USB drive.. total cost less than $140 for a 2TB or even 3TB drive. Then you will have a real backup. TM you can never tell if it can restore a full computer unless you test it.. all backups are proven in the restore.. nothing else .. !!

CCC (and other similar tools) can make a bootable USB disk with the full image of your existing computer install.. do it today.. do it again before you upgrade.

Each time actually boot from the image.. so you are sure the image is perfect.

Then when you upgrade.. you cannot lose any info. You can corrupt TM all you like and it will not matter one bit.. because you are not dependent on it. That is the only way to have a backup that can be depended on.

The issue is not accessing the backup once the name is changed by finder.. that is trivial.. any computer can access the backup with a bit of effort.. what you want is TM to not work. It is TM that I am trying to stop access for.. not finder.

But I think you are over analyzing.. If you are really concerned.. please please make a secondary backup today. Do it anyway you like.. Otherwise please just proceed with the update and don't worry about it. We are going around in circles.