Copying to a backup - how to 'mirror' the content?

ClassicCar · 21 Jul 2024 at 14:21

Good afternoon,

I regularly back-up my PC drives to external SSD's, normally by just copying and pasting.

The issue I face is having deleted and changed some of the files on my PC (which happens regularly), if I simple copy and paste onto the backup it obviously adds the new files to the backup, but it doesn't remove any files - i.e. it is no longer representative of my PC, it's mishmash of historical files that are continually added to.

A way around this is to delete everything off the backup and do a new copy every time I make a backup - but that takes a long time.

Is there any tool which will automatically adjust the backup to my PC contents - i.e. identifying what has changed and what hasn't and moving the files appropriately?

Many thanks.

Rroff · 21 Jul 2024 at 14:46

There is various backup software but simplest way would be to use a command prompt with something like:

Code:

robocopy [source] [destination] /E /PURGE /COPY:DAT /R:10 /W:3

or

robocopy c:\temp\source c:\temp\destination /MIR /COPYALL /DCOPY:DAT /R:100 /W:3

And replace [source] and [destination] with the relevant paths i.e. c:\ g:\ or whatever.

For an online OS drive copying the whole contents can cause issues unless you use software designed for that.

Make sure you get the source and destination the right way around though or it will purge the wrong files.

EDIT: Probably worth Googling a guide on robocopy

5abr3 · 21 Jul 2024 at 14:48

I don't have a suggestion on software to do what you want specifically - but generally being able to walk back to a file (or even a previous version) that you deleted and find in some months that you need is a good thing.

So it might be worth a rethink of what you are trying to achieve and the failure modes you do/don't want to protect against, especially if there's plenty of space on the removable media.

joey1211 · 21 Jul 2024 at 14:56

Syncback using the non deletion backup option. It moves and renames any changed files to a subfolder.

ClassicCar · 21 Jul 2024 at 18:13

joey1211 said:
Syncback using the non deletion backup option. It moves and renames any changed files to a subfolder.

Thanks for this - have downloaded and it looks good, although I haven't quite figured out the 'non-delete aspect of it, and if I run a sequence of files to my external drive it'll do one then delete it in the next runthrough, so I'll have to figure that out.

andshrew · 21 Jul 2024 at 19:36

FreeFileSync is another alternative if you want something with a graphical interface.

FreeFileSync

Download FreeFileSync 13.8. FreeFileSync is a free open source data backup software that helps you synchronize files and folders on Windows, Linux and macOS.

freefilesync.org

Bubo · 22 Jul 2024 at 10:38

I also use Syncback Free. Set it to mirror main drive to external such that:

If a file is only on the source drive it gets copied to destination.
If a file only exists on destination it gets deleted from destination.
If a file has changed on source it overwrites the same file on destination.
Set some filters to ignore certain files types so they never get copied from source to destination.