syntax
$ sync [option] [file]
To sync all the cached files to the permanent memory which belongs to the current user
$ sudo sync
To sync only file data, no unneeded metadata
$ sudo sync -d /home/ilugc/file1.txt
To sync all the files in dir
$ sudo sync -f /home/ilugc/Downloads
To sync the cache data of the mounted partition
$ sudo sync /dev/vda1
$ sudo sync /var/log/syslog
regards,
T.Dhanasekar