새로 서버 구성후 MariaDB 에러때문에 journalctl -xe  로 상태를 살펴보니 가관이 아니네요

root 권한 탈취하려고 득달처럼 계속 시도를 하는군요.

일단 MariaDB 오류 해결이 우선이라 root 탈취 시도 대비는 잠시 접어두고...

저는 다시 구글 검색의 세계로 풍덩

[root@localhost etc]# systemctl start mariadb

Job for mariadb.service failed because the control process exited with error code. See "systemctl status mariadb.service" and "journalctl -xe" for details.

[root@localhost etc]# journalctl -xe

Jul 30 03:44:15 localhost.localdomain sshd[23175]: PAM 5 more authentication failures; logname= uid=0 euid=0 tty=ssh ruser= rhost=118.212.135.3  user=root

Jul 30 03:44:15 localhost.localdomain sshd[23175]: PAM service(sshd) ignoring max retries; 6 > 3

Jul 30 03:44:15 localhost.localdomain sshd[23181]: Invalid user postgres from 185.165.29.117

Jul 30 03:44:15 localhost.localdomain sshd[23181]: input_userauth_request: invalid user postgres [preauth]

Jul 30 03:44:15 localhost.localdomain sshd[23181]: pam_unix(sshd:auth): check pass; user unknown

Jul 30 03:44:15 localhost.localdomain sshd[23181]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=185.165.29.117

Jul 30 03:44:16 localhost.localdomain polkitd[582]: Registered Authentication Agent for unix-process:23183:132860522 (system bus name :1.4462 [/usr/bin/pkttyagent --notify-fd 5 --fallback], object path /org/fr

Jul 30 03:44:16 localhost.localdomain systemd[1]: Starting MariaDB database server...

-- Subject: Unit mariadb.service has begun start-up

-- Defined-By: systemd

-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel

-- 

-- Unit mariadb.service has begun starting up.

Jul 30 03:44:16 localhost.localdomain sshd[23179]: Failed password for root from 61.177.172.66 port 19806 ssh2

Jul 30 03:44:16 localhost.localdomain sshd[23179]: pam_succeed_if(sshd:auth): requirement "uid >= 1000" not met by user "root"

Jul 30 03:44:16 localhost.localdomain mysqld[23341]: 2017-07-30  3:44:16 139671304394880 [Warning] 'THREAD_CONCURRENCY' is deprecated and will be removed in a future release.

Jul 30 03:44:16 localhost.localdomain mysqld[23341]: 2017-07-30  3:44:16 139671304394880 [Note] /usr/sbin/mysqld (mysqld 10.2.7-MariaDB-log) starting as process 23341 ...

Jul 30 03:44:16 localhost.localdomain mysqld[23341]: 2017-07-30  3:44:16 139671304394880 [Note] Using unique option prefix 'myisam_recover' is error-prone and can break in the future. Please use the full name 

Jul 30 03:44:16 localhost.localdomain mysqld[23341]: 2017-07-30  3:44:16 139671304394880 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins

Jul 30 03:44:16 localhost.localdomain mysqld[23341]: 2017-07-30  3:44:16 139671304394880 [Note] InnoDB: Uses event mutexes

Jul 30 03:44:16 localhost.localdomain mysqld[23341]: 2017-07-30  3:44:16 139671304394880 [Note] InnoDB: Compressed tables use zlib 1.2.7

Jul 30 03:44:16 localhost.localdomain mysqld[23341]: 2017-07-30  3:44:16 139671304394880 [Note] InnoDB: Using Linux native AIO

Jul 30 03:44:16 localhost.localdomain mysqld[23341]: 2017-07-30  3:44:16 139671304394880 [Note] InnoDB: Number of pools: 1

Jul 30 03:44:16 localhost.localdomain mysqld[23341]: 2017-07-30  3:44:16 139671304394880 [Note] InnoDB: Using SSE2 crc32 instructions

Jul 30 03:44:16 localhost.localdomain mysqld[23341]: 2017-07-30  3:44:16 139671304394880 [Note] InnoDB: Initializing buffer pool, total size = 2G, instances = 8, chunk size = 128M

Jul 30 03:44:16 localhost.localdomain mysqld[23341]: 2017-07-30  3:44:16 139671304394880 [Note] InnoDB: Completed initialization of buffer pool

Jul 30 03:44:16 localhost.localdomain mysqld[23341]: 2017-07-30  3:44:16 139668378109696 [Note] InnoDB: If the mysqld execution user is authorized, page cleaner thread priority can be changed. See the man page

Jul 30 03:44:16 localhost.localdomain mysqld[23341]: 2017-07-30  3:44:16 139671304394880 [Note] InnoDB: Highest supported file format is Barracuda.

Jul 30 03:44:16 localhost.localdomain mysqld[23341]: 2017-07-30  3:44:16 139671304394880 [Note] InnoDB: 128 out of 128 rollback segments are active.

Jul 30 03:44:16 localhost.localdomain mysqld[23341]: 2017-07-30  3:44:16 139671304394880 [Note] InnoDB: Creating shared tablespace for temporary tables

Jul 30 03:44:16 localhost.localdomain mysqld[23341]: 2017-07-30  3:44:16 139671304394880 [Note] InnoDB: Setting file './ibtmp1' size to 12 MB. Physically writing the file full; Please wait ...

Jul 30 03:44:16 localhost.localdomain mysqld[23341]: 2017-07-30  3:44:16 139671304394880 [Note] InnoDB: File './ibtmp1' size is now 12 MB.

Jul 30 03:44:16 localhost.localdomain mysqld[23341]: 2017-07-30  3:44:16 139671304394880 [Note] InnoDB: Waiting for purge to start

Jul 30 03:44:16 localhost.localdomain mysqld[23341]: 2017-07-30  3:44:16 139671304394880 [Note] InnoDB: 5.7.18 started; log sequence number 1621040

Jul 30 03:44:16 localhost.localdomain mysqld[23341]: 2017-07-30  3:44:16 139668217644800 [Note] InnoDB: Loading buffer pool(s) from /var/lib/mysql/ib_buffer_pool

Jul 30 03:44:16 localhost.localdomain mysqld[23341]: 2017-07-30  3:44:16 139668217644800 [Note] InnoDB: Buffer pool(s) load completed at 170730  3:44:16

Jul 30 03:44:16 localhost.localdomain mysqld[23341]: 2017-07-30  3:44:16 139671304394880 [Note] Plugin 'FEEDBACK' is disabled.

Jul 30 03:44:16 localhost.localdomain mysqld[23341]: 2017-07-30  3:44:16 139671304394880 [ERROR] /usr/sbin/mysqld: unknown variable 'innodb_additional_mem_pool_size=16M'

Jul 30 03:44:16 localhost.localdomain mysqld[23341]: 2017-07-30  3:44:16 139671304394880 [ERROR] Aborting

Jul 30 03:44:17 localhost.localdomain sshd[23382]: reverse mapping checking getaddrinfo for 3.135.212.118.adsl-pool.jx.chinaunicom.com [118.212.135.3] failed - POSSIBLE BREAK-IN ATTEMPT!

Jul 30 03:44:17 localhost.localdomain sshd[23382]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=118.212.135.3  user=root

Jul 30 03:44:17 localhost.localdomain sshd[23382]: pam_succeed_if(sshd:auth): requirement "uid >= 1000" not met by user "root"

Jul 30 03:44:17 localhost.localdomain sshd[23181]: Failed password for invalid user postgres from 185.165.29.117 port 42392 ssh2

Jul 30 03:44:18 localhost.localdomain sshd[23181]: Received disconnect from 185.165.29.117: 11: Bye Bye [preauth]

Jul 30 03:44:18 localhost.localdomain sshd[23179]: Failed password for root from 61.177.172.66 port 19806 ssh2

Jul 30 03:44:18 localhost.localdomain sshd[23179]: Received disconnect from 61.177.172.66: 11:  [preauth]

Jul 30 03:44:18 localhost.localdomain sshd[23179]: PAM 2 more authentication failures; logname= uid=0 euid=0 tty=ssh ruser= rhost=61.177.172.66  user=root

Jul 30 03:44:18 localhost.localdomain systemd[1]: mariadb.service: main process exited, code=exited, status=7/NOTRUNNING

Jul 30 03:44:18 localhost.localdomain systemd[1]: Failed to start MariaDB database server.

-- Subject: Unit mariadb.service has failed

-- Defined-By: systemd

-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel

-- 

-- Unit mariadb.service has failed.

-- 

-- The result is failed.

Jul 30 03:44:18 localhost.localdomain systemd[1]: Unit mariadb.service entered failed state.

Jul 30 03:44:18 localhost.localdomain systemd[1]: mariadb.service failed.

Jul 30 03:44:18 localhost.localdomain polkitd[582]: Unregistered Authentication Agent for unix-process:23183:132860522 (system bus name :1.4462, object path /org/freedesktop/PolicyKit1/AuthenticationAgent, loc

Jul 30 03:44:19 localhost.localdomain sshd[23382]: Failed password for root from 118.212.135.3 port 59238 ssh2

Jul 30 03:44:20 localhost.localdomain sshd[23382]: pam_succeed_if(sshd:auth): requirement "uid >= 1000" not met by user "root"

[root@localhost etc]#