Mariabackup Throws Unknown Argument Error I have just installed the MariaDB backup tool based on Percona Xtrabackup, Mariabackup, on my CentOS 7 system with MariaDB v10.1. However, when I try to test using this tool, it fails immediately complaining about an unknown argument.

I tried running this command as a full backup, as a full backup using the --xbstream option to pipe it through gzip, and as a full backup using gzip and OpenSSL. I also tried GPG with gzip.

Here are the commands I've tried:

With gzip/openssl:

mariabackup --user=root --password= `cat /etc/psa/.psa.shadow ` --backup     --stream=xbstream | gzip | openssl  enc -aes-256-cbc -k password123 &gt;     backup.xb.gz.enc


with gzip/gpg:

mariabackup --user=root --password= `cat /etc/psa/.psa.shadow ` --backup --stream=xbstream | gzip | gpg -c --passphrase password123 --batch --yes -o backup.xb.gzip.gpg


With gzip:

mariabackup --user=root --password= `cat /etc/psa/.psa.shadow ` --backup --stream=xbstream | gzip &gt; backup.xb.gz


And just straight up:

mariabackup --user=root --password= `cat /etc/psa/.psa.shadow ` --backup --target-dir=/root/sql_dumps/


And here's the output:

Info: Using unique option prefix 'backup' is error-prone and can break in the future. Please use the full name backup_encrypted instead.  

mariabackup: Error: unknown argument: '$AES-128-CBC$GzzuTl0rBKRyCngfmWSypg==$JAmMp9hcbIQ/MTrzqCQ8eWIFQGixpUjZ7ESQqNLfuJM='
I'm pretty sure this error was caused by supplying the wrong username. After I resolved that, the error went away and the backup initiated.