Following Apple's instructions I have prepared a new 4TB drive so that I can transfer data from my now full 2TB Time Machine. It's been over an hour and from what I've read, it could take days. Is this normal? Does anyone have experience with moving a Time Machine backup to a new, larger drive?
MacBook Pro
Yes, moving TB's of data takes a long time -- How is your disk attached to your MacBook (USB or Thunderbolt or ???)? Do some simple math and use what Activity Monitor shows you for the transfer rates - divide total storage to move by the average transfer rate for that disk (click on the Disk tab to see this info at the bottom-center of the window) and that will give you an approximate time that it should take.
I would suggest another option if you can attach both drives at once -- rather than simply move the TM bits from one drive to another, just add the second drive to the TM "pool" of available drives. This will allow TM to use one drive for one backup and then the other drive for the next (sort of a ping-pong behavior). Your effective backup storage space is now the sum of the two drives. Backups are not split up across drives - each drive will contain full backups independently of each other - the beauty of this is if one drive fails you have a second backup available without doing anything else.
Good luck...
Yes, moving TB's of data takes a long time -- How is your disk attached to your MacBook (USB or Thunderbolt or ???)? Do some simple math and use what Activity Monitor shows you for the transfer rates - divide total storage to move by the average transfer rate for that disk (click on the Disk tab to see this info at the bottom-center of the window) and that will give you an approximate time that it should take.
I would suggest another option if you can attach both drives at once -- rather than simply move the TM bits from one drive to another, just add the second drive to the TM "pool" of available drives. This will allow TM to use one drive for one backup and then the other drive for the next (sort of a ping-pong behavior). Your effective backup storage space is now the sum of the two drives. Backups are not split up across drives - each drive will contain full backups independently of each other - the beauty of this is if one drive fails you have a second backup available without doing anything else.
Good luck...
Thanks for your quick response. I really like your idea of adding the 2nd drive and having both drives doing Time Machine duty. When I noticed that the 2TB USB drive that I use for Time Machine backups was getting very full, I researched the issue a little and was under the impression that Time Machine would simply delete older backups (going back to 2015) to make room for the new ones. However, the 2TB drive now shows "0 MB Free" and will no longer perform backups. I guess it stopped dropping old files. So I got a 4TB drive to deal with it. I wish I had known about simply adding another drive before I started to transfer all of the data from the old drive. Given the "backup failure" messages from Time Machine using the 2TB drive I assumed that it would not take anymore data. But you are saying that by adding the 4TB drive and leaving the 2TB in place, that BOTH drives would be used and that the full 2TB drive would not cause a "backup failure?"
Right now I am getting a message that says "Preparing to copy to "Seagate 4TB Time Machine" and the number of items to copy has been slowly, but steadily increasing. It took about 10 minutes to show 125 items. It seemed to stick there for awhile, then started to slowly increase. It's now been at 169,004 items for the last 10 minutes after about 2 hours total.
Looking at the Activity Monitor, if I am reading it correctly, it shows: Data read/sec 229 KB and Data written/346 KB. However these figures change all the time. Data read/sec can be 0KB and Data written/sec can be 3.0 KB. It's all over the place.
At this point, I think I will give it 24 hours and see what happens. If it stays stuck or does not progress at an encouraging rate, perhaps I will pull the plug and reformat the 4TB drive and try your suggestion.
BTW.. my MacBook Pro is a late 2013 and I believe has 2 USB slots (USB 2.0 not 3.0)
Maximum speed for a USB 2 connection is about 450Mbits/sec or about 45MBytes/sec - that is theoretical, and my experience has been about 30MBytes/sec in reality. Look at Activity Monitor in the "Disk" tab and you will see the actual speed of what is going on.
Given that bit of information it should take about 18 hours to transfer 2TB of stuff.
Since the old TM disk is completely full, TM should have been removing oldest backups to make room for new backups. But it isn't apparently doing that. Try this to see a list of all your backups in a Terminal window:
tmutil listbackups
Given that your old TM disk was completely full, I think your best move is to let the copy finish to the new larger drive, then manually erase the old drive and then add it to the TM setup -- this will let you keep all the old backups and then start the ping-pong TM backups.
Good luck...
Ocalagator wrote:
Is this normal? Does anyone have experience with moving a Time Machine backup to a new, larger drive?
yes it is normal.
Thanks. If it's normal, I'll just wait it out for awhile.
Thanks for the help. It looks like it will take awhile, but I think I will follow your suggestion and ride it out and THEN add the 2TB drive back into the picture.
Address the issue of how long it takes to copy Time Machine files to a new external drive. It's been over an hour and from what I've read, it could take days. Is this normal?
