MariaDB – How to Fix mariabackup Error: cannot mkdir 2: /data/backups/mariadb/

Trying to use mariabackup to take backup of all our databases. First created backup directory as

mkdir -p /mnt/data/backup/mariadb
chown -R mysql:mysql /mnt/data/backup/mariadb

And proceed to do backup

# mariabackup --backup --target-dir=/mnt/data/backups/mariadb/ --user=root --password=xxxxxxxx
[00] 2022-02-06 11:28:46 Connecting to MySQL server host: localhost, user: root, password: set, port: not set, socket: /mnt/data/mysql/mysql.sock
[00] 2022-02-06 11:28:46 Using server version 10.3.28-MariaDB
mariabackup based on MariaDB server 10.3.28-MariaDB Linux (x86_64)
[00] 2022-02-06 11:28:46 uses posix_fadvise().
[00] 2022-02-06 11:28:46 cd to /mnt/data/mysql/
[00] 2022-02-06 11:28:46 open files limit requested 0, set to 1024
[00] 2022-02-06 11:28:46 mariabackup: using the following InnoDB configuration:
[00] 2022-02-06 11:28:46 innodb_data_home_dir = 
[00] 2022-02-06 11:28:46 innodb_data_file_path = ibdata1:12M:autoextend
[00] 2022-02-06 11:28:46 innodb_log_group_home_dir = ./
[00] 2022-02-06 11:28:46 InnoDB: Using Linux native AIO
2022-02-06 11:28:46 0 [Note] InnoDB: Number of pools: 1
[00] 2022-02-06 11:28:46 Error: cannot mkdir 2: /mnt/data/backups/mariadb/

tried goggling and various options it did not worked so finally tried without –target-directory option and did backup again and it worked successfully and got this

# ls -ld /mnt/data/backup
drwxr-xr-x 3 mysql mysql 21 Feb  6 11:41 /mnt/data/backup

# pwd
/mnt/data/mysql

# ll
total 8
drwxr-xr-x  3 mysql mysql   21 Feb  6 11:41 backup
drwxr-xr-x 27 mysql mysql 4096 Feb  4 19:07 mysql
drwx------ 27 root  root  4096 Feb  6 11:22 xtrabackup_backupfiles

What did I do wrong or how do I run this with —-target-directory