Internal HDD used for Time Machine out of space...best way to add more space?

[HXGuyAZ]

I have a 3TB internal hard drive that's used for Time Machine and it's out of space. What would be the best way to add more space so that I can keep what's already in Time Machine and be able to continue backing up?

I saw on this site that I can add a second drive, say another 3TB, would that work seamlessly with Time Machine?

Or would it be better to buy a 6TB HDD and copy over the current TM file and just use one drive?

 

[Zwhaler]

6TB ftw. They're about $300 last I checked.

 

[h9826790]

If you still have empty slot. Get another 6T HDD, and then use BOTH for backup. Time Machine will automatically swap the backup disk every hour. So now, you have 2 backup, no need to worry about the backup HDD fail and lost the backup only files (e.g. some old system files). And the new 6T HDD can solve the capacity problem.

 

[HXGuyAZ]

I do have 1 empty slot left. If it ok if both drives are not the same size though? The current Time Machine drive is 3TB and full (Time Machine keeps giving an error that it can't backup anymore)...if I add a 6TB drive and use both the full 3TB and the new 6TB together, how will that work with Time Machine swapping between them every hour?

 

[h9826790]

Both backup works independently. So, different HDD size is not a problem. I am currently running a 2T Time Capsule and a 3T Time Capsule.



As you can see, both TC have different HDD size. The bigger one has the backup up to July, and still has some free space. The smaller one only has the backup up to 2nd Sep, and is almost full.

If you simply install a 6T HDD and add that to the backup disk list. Then the Time Machine will automatically backup your Mac to either one of them. One hour later, it will backup everything to the other HDD. All your current backup still available in the old 3T HDD. And the 6T HDD only has the backup from when it install.

Since your 3T is too full and can't cleanup or backup anymore. Time Machine most likely will backup your Mac to the 6T HDD only but still leave the 3T HDD untouched.

So, you better copy all your current data to the new 6T HDD and then let the Time Machine to continue the backup.

What I recommend is:

1) Install the new 6T HDD.
2) Copy the old backup to this new HDD.
3) Add it to the backup HDD list in Time Machine.
4) Select "Backup now" to perform backup.
5) If backup successful, enter time machine to check if the old back is actually available.
6) Leave this config for few days, make sure the new 6T works well with all the backup.
7) Manually clean up the 3T HDD, or format it to start new backup.
8) From this point. You Time Machine will backup your Mac to the 3T HDD. One hour later, backup to the 6T HDD. And then back to the 3T HDD an hour later.....

 

[HXGuyAZ]

Thanks for the detailed reply. Couple other questions...

Is the point of two back up drives to be redundant in case one fails? I'm not really looking for that as I also have a non Time Machine backup using Carbon Copy Cloner which backs up every night so ideally for TM, I'd like it to just be able to archive as far back as possible.

If using two drives, the 3TB and 6TB, will TM treat it like 9TB total or is it going to just make double copies?

 

[h9826790]

You will have double copies. If you prefer use the CCC backup as fail safe, then may be no need to have 2 TM backup. So you can copy the old backup to the new 6T HDD, and then format the old 3T HDD for other usage.

 

[HXGuyAZ]

Sucks, was hoping it could keep the full 3TB drive as the oldest backup and then use the new 6TB going forward, so essentially it would be 9TB of TM backups.

 

[Sko]

... so essentially it would be 9TB of TM backups.

You could always deactivate the 3TB drive and start with the 6TB from scratch. So you get a complete backup from day x with incrementals to day y on the 3TB drive, then a complete backup from day y and ongoing incrementals on the 6TB.

 

[h9826790]

If you just add a new 6T HDD to the TM disk list and doing nothing else, this will be more or less the same as what you want because,

1) TM will do nothing to your 3T HDD because it's too full. It won't even remove the oldest backup as what you said. Or you can lock the disk to make sure TM can't make any change to it.

2) TM can only use the new 6T HDD to backup the new files, until it's full. And no duplicated old backups files in this HDD.

3) So, at the end of the day, you will have 9T backup storage. However, you have to choose the correct disk manually to restore the target files.

The downside of this setup is that your TM can't backup every hour, but reduce the frequency to every other hour. It's because every time when TM try to backup to the 3T HDD, error occur, and that hourly backup will be skipped.

Of course, you can remove the 3T HDD from the TM disk list. And only add it back when you need it. Then your TM will able to perform the normal hourly backup to the 6T HDD.

 

[HXGuyAZ]

Hmm that would have been good..but TM has erased everything up until just 3 days ago since the disk was full, so really there isn't much point to the old 3TB drive. Thanks for the help guys.