How to achieve a mirror copy in Linux?

I want to make two directories synchronized. I know there is a robocopy /MIR command in Windows that can achieve this. Ex:

robocopy D:test1 E:Backup /MIR

When there is a file updated or deleted, the backup directory can keep synchronization.

I have tried in Linux through the rsync command like this:

rsync -a /usr/test /usr/backup

but when I delete a file under /usr/test and then run this command, the deleted file still exists in /backup/test — the two directories can’t keep asynchronization. So, how can I achieve the synchronization of two directories in Linux?

Answer

rsync has a --delete option which does what was asked:

 --delete                delete extraneous files from dest dirs

It has a lot of related options.

Further reading:

• rsync(1)
• Commonly Used rsync Arguments