mariadb-dump --dir can not be run as root user

root@HOST:~/sqldumps# ll

total 8

drwxr-xr-x 2 mysql mysql 4096 Nov 30 05:05 ./

drwx------ 8 root  root  4096 Nov 30 05:05 ../

root@HOST:~/sqldumps# mariadb-dump --dir=. --all-databases --dump-slave 

--

-- The following is the SQL position of the replication taken from SHOW SLAVE STATUS at the time of backup.

-- Use this position when creating a clone of, or replacement server, from where the backup was taken.

-- This new server will connects to the same primary server(s).

--

-- A corresponding to the below dump-slave CHANGE-MASTER settings to the slave gtid state is printed later in the file.

CHANGE MASTER '' TO MASTER_LOG_FILE='host-bin.002051', MASTER_LOG_POS=310524976;

mariadb-dump: Got error: 1: "Can't create/write to file '/root/sqldumps/mysql/column_stats.txt' (Errcode: 13 "Permission denied")" when executing 'SELECT INTO OUTFILE'

root@HOST:~/sqldumps# ll

total 12

drwxr-xr-x 3 mysql mysql 4096 Nov 30 05:06 ./

drwx------ 8 root  root  4096 Nov 30 05:05 ../

drwx------ 2 root  root  4096 Nov 30 05:06 mysql/

root@HOST:~/sqldumps# ll mysql/

total 20

drwx------ 2 root  root  4096 Nov 30 05:06 ./

drwxr-xr-x 3 mysql mysql 4096 Nov 30 05:06 ../

-rw-r--r-- 1 root  root  2022 Nov 30 05:06 column_stats.sql

-rw-r--r-- 1 root  root  1707 Nov 30 05:06 general_log.sql

-rw-r--r-- 1 root  root  1927 Nov 30 05:06 slow_log.sql

root@HOST:~/sqldumps# 

mysql:x:110:110:MariaDB Server,,,:/nonexistent:/bin/false

# switched to

mysql:x:110:110:MariaDB Server,,,:/nonexistent:/bin/bash

mysql@HOST:/data/mysql_dumps$ mariadb-dump --dir=. --all-databases --dump-slave 

--

-- The following is the SQL position of the replication taken from SHOW SLAVE STATUS at the time of backup.

-- Use this position when creating a clone of, or replacement server, from where the backup was taken.

-- This new server will connects to the same primary server(s).

--

-- A corresponding to the below dump-slave CHANGE-MASTER settings to the slave gtid state is printed later in the file.

CHANGE MASTER '' TO MASTER_LOG_FILE='host-bin.002051', MASTER_LOG_POS=320087919;

-- The deferred gtid setting for slave corresponding to the dump-slave CHANGE-MASTER follows

-- GTID position to start replication:

-- SET GLOBAL gtid_slave_pos='0-1-1035443654';

mysql@HOST:/data/mysql_dumps$ ls -alh

total 60K

drwxr-xr-x 5 mysql mysql 4.0K Nov 30 05:14 .

drwxr-xr-x 5 mysql mysql 4.0K Nov 30 04:36 ..

drwx------ 2 mysql mysql 4.0K Nov 30 05:14 db1

drwx------ 2 mysql mysql  12K Nov 30 05:14 db2

drwx------ 2 mysql mysql  36K Nov 30 05:15 db3

backups@HOST:/data/mysql_dumps$ mariadb-dump --dir=. --all-databases --dump-slave

--

-- The following is the SQL position of the replication taken from SHOW SLAVE STATUS at the time of backup.

-- Use this position when creating a clone of, or replacement server, from where the backup was taken.

-- This new server will connects to the same primary server(s).

--

-- A corresponding to the below dump-slave CHANGE-MASTER settings to the slave gtid state is printed later in the file.

CHANGE MASTER '' TO MASTER_LOG_FILE='host-bin.002051', MASTER_LOG_POS=325744788;

mariadb-dump: Got error: 1: "Can't create/write to file '/data/mysql_dumps/mysql/column_stats.txt' (Errcode: 13 "Permission denied")" when executing 'SELECT INTO OUTFILE'

backups@HOST:/data/mysql_dumps$ ll

total 12

drwxr-xr-x 3 backups mysql   4096 Nov 30 05:20 ./

drwxr-xr-x 5 mysql   mysql   4096 Nov 30 04:36 ../

drwx------ 2 backups backups 4096 Nov 30 05:20 mysql/

backups@HOST:/data/mysql_dumps$ cd mysql/

backups@HOST:/data/mysql_dumps/mysql$ ll

total 20

drwx------ 2 backups backups 4096 Nov 30 05:20 ./

drwxr-xr-x 3 backups mysql   4096 Nov 30 05:20 ../

-rw-rw-r-- 1 backups backups 2022 Nov 30 05:20 column_stats.sql

-rw-rw-r-- 1 backups backups 1707 Nov 30 05:20 general_log.sql

-rw-rw-r-- 1 backups backups 1927 Nov 30 05:20 slow_log.sql