Formatting a new Time Machine backup drive

[DRDR1]

I currently have an external drive on-site which I use for my Time Machine backups.
I have just been given a second drive (Seagate) that I would like to use occasionally as a second backup and for it to be kept off site.
This new drive has previously been used as a Time Machine backup on my daughters laptop. It is full.
Can anyone tell me how to correctly format the disk for this purpose.? I would not like to confuse or damage my existing Time Machine backups.
I have an imac and am using El Capitan 10.11.6
Thanks

 

[Cory Cooper]

Hello and welcome.

Do you need to save any of the Time Machine backups from your daughter's Mac that are currently on the Seagate? If not, you can unmount and disconnect your current TM drive, connect the Seagate, erase it using Disk Utility, then setup Time Machine to use multiple disks as outlined here: How to use multiple hard drives with Time Machine. It's a good idea to disconnect your current TM drive, so you don't accidentally erase it.

Let us know if that helps,

C

 

[DRDR1]

Cory, thanks for that. Sorry about the delay in replying, I have been away.
Well I disconnected my normal backup drive and mounted my daughter's old
disk. It immediately knew what it was and asked if I wanted to keep any of
the data, which I did not.
It then created a new backup without further ado
Problem I have is that there is no differentiation between the disks. when
I change the disk it tells my it is a different one since last time and is
it ok.
Somehow I thought it would allow me to name the disks so it is completely
clear as to which one is in use.
rgds