mysql@bootstrap.service: Unit not found.

MySQL & MariaDB Other MySQL® Questions
4

Hi @OleksiiKa

As I can see you are trying to install Percona XtraDB Cluster 5.7

For this version command systemctl start mysql@bootstrap.service is supported only for centos7 and centos8

For debian based OS it is needed to use /etc/init.d/mysql bootstrap-pxc

For more details please see https://www.percona.com/doc/percona-xtradb-cluster/5.7/bootstrap.html