timemachine wrecked backups when HD upgraded

[karlreed]

Just had timemachine delete most of backup images to make room for a whole of HD image. I have upgraded my HD to SSD, and, therefore have a new physical HD.
My advice is to be VERY careful! I lost almost two years of images. I do have CCC for incremental backups, but, TM is great for retrieving working preferences and such.
So, I would expect TM to do the same thing under 10.10.1 as well.
Karl

 

[IWT]

Hi karlreed

Time Machine (TM), as I understand it, is not meant to be a "long term" store of images or anything else. On first use, it copies everything from your IHD including preferences, photos, music and so on.

Then, hourly (and subsequently weekly etc), it only backs up things that have changed since the last BU. In this way, it conserves space. If/when the TM disk gets full, it deliberately deletes the oldest files to make room for the latest changes.

If you have precious material - music, movies, photos, documents which you wish to retain more or less indefinitely, then these should be copied to an Ext HD and updated or amended manually.

In your case, TM behaved as it is intended to do. You changed your IHD and, if I understand you correctly, you then tried to BU the new IHD. To make space for this, TM had to delete files.

Better to have used a new EHD as TM for your new system.

TM is great for what it does, but is not bootable. You have CCC which is bootable and can be tasked to sync on a timed basis - say, once a week. In addition, I suggest an additional EHD for those important things on your Mac.

Ian

 

[MacInWin]

As IWT says, neither CCC nor TM is designed as a hierarchical storage, but as backup software. Anything you want in deep storage should be on either a separate EHD, or in the cloud, or on DVD.

 

[karlreed]

I was hoping TM would accept the new Macintosh HD

The points you both make are quite valid, however, since the new Macintosh HD is a cloned copy of the original, and, there were only incremental differences, I expected it to simply continue where it left off, and copy the complete disk, which it already has.

Of course, I have real incremental backups, and, if need be, can reach back some 12 years (Using Retrospect). For the last four or five years, I have used CCC, and have four live incremental backups, all on different drives. I also have three clones of my HD. I am moving to Yosemite as soon a I can resolve some issues with software I depend upon. I also do have a spare tm disk as well. Right now, my SSD Hd has a large partition for my current systems 10.6.8, and a small partition for 10.10.1 which I am using for testing. When I am ready, I will drop a small clone of 10.6.8 on the latter partition, and, upgrade the main partition.

What you say about TM is correct, however, I have found it very valuable when prferences are corrupted for some reason, and I can move back to a set that works.

Anyway, many thanks for the comments. .
Karl

 

[MacInWin]

No, it is an entirety different device. Even if you think it's the same, to the system it's totally different and needed a full backup.