Cloning Time Machine backup to run two backups at independent locations

Question

I would like to check if the following scenario will work.

Present set-up

• Backing up to Time Capsule via Time Machine
• Amassed over 2 TB
• I want to build redundancy to cover for ageing Time Capsule

Desired Outcome

• Keeping existing backup on Time Capsule
  • This will be decommissioned when it fails
• Cloning the backup .backupbundle image file to new network drive and using that backup in parallel with the existing Time Machine backup
• XXX.backupbundle maintained at Time Capsule and new network drive

Steps

1. Connect new network drive (done)
2. Copy the existing XXX.backupbundle file from Time Capsule to the new network drive (finishing now)
3. Adding new network drive to time machine (to do)
4. Selecting "use both" to maintain two identical backups at two locations (to do)

Question

With respect to the outstanding points 3 and 4:

1. is there anything else I should do to ensure that Time Machine will recognise the XXX.backupbundle file that was copied to another location.
2. any other points worth considering before I start interacting with the Time Machine settings?

Answer 1

It’s very simple to add two drives as destinations in time machine (or three or four) as the system just backs up to them round robin. You can rotate backups offline and remove them and add them back to the mix when they return.

I would not clone your existing backup until you’re ready to retire it. Then you would likely break open the enclosure and do a disk to disk clone. You will have a dramatically faster operation to copy the disk block for block and attached to the fastest computer you have directly, as opposed to letting the TimeCapsule controller throttle the speed.

For now, get set up with a second destination and build up current backups going forward is my advice.

Why:

• it’s easy and supported to restore any key files you know you need from the backup and let them go to the new drive.
• The old backup will likely be stable for many years once you take it out of rotation
• The process to clone is exceptionally slow
• The process to break the identity of a clone and have it be a new destination is finicky and prone to error, requiring a second “clone” if it fails.