How much space for files in a RAID 1 array (two disks of 1 Tb each)?

Question

linux

There is a raid an array in which two disks in a mirror on 1 Tb. Raid 1. Made with mdamd on ubuntu server.
I'm trying to transfer files to another 2 Tb disk via SAMBA. When indexing files, the system says that there are 12 million files on the shared folder and it all takes 4.4 Tb. Accordingly sees an error.
As on a mirror raid where 1 Tb places fit 4.4 Tb. and why can't I transfer it all to a 2 TB disk?

Answer 1

1. What file system?
2. When copying files, did you take into account links? Linux is very fond of symbolic ones for files and directories, and even hardlinks for files that cannot be distinguished at all.

Answer 2

df -hwhat does it show?
Did you check the file system for errors?

Answer 3

Unmount the filesystem and do a stupid dd if=/dev/md0 of=/dev/ on the big disk partition. And there will be a copy of the entire file system with all soft / hard links, sparse files and everything you need. Then resizee2fs to expand the filesystem to the capacity of the partition.
And if you want to smoothly replace the array with more capacious ones, then you don’t need to copy files at all. Add bigger drives, wait for sync, remove old drives and do resize2fs ru.stackoverflow.com/a/637847/203622