title: Status: "MariaDB server is down"
body: <p>Hope someone can help me:</p>
  
  <p>I have many sites running on my server and I am using mariadb.
  when I do:</p>
  
  <pre><code>sudo service mysql restart
  </code></pre>
  
  <p>I get:</p>
  
  <pre><code>Job for mariadb.service failed because the control process exited with 
  error code. See "systemctl status mariadb.service" and "journalctl -xe" 
  for details.
  </code></pre>
  
  <blockquote>
    <p>systemctl status mariadb.service</p>
  </blockquote>
  
  <pre><code>    mariadb.service - MariaDB database server
  
      Loaded: loaded (/lib/systemd/system/mariadb.service; enabled; vendor preset: enabled)
  
      Drop-In: /etc/systemd/system/mariadb.service.d
               └─migrated-from-my.cnf-settings.conf
      Active: failed (Result: exit-code) since Thu 2017-09-14 03:16:51 UTC; 1min 6s ago
      Process: 13247 ExecStart=/usr/sbin/mysqld $MYSQLD_OPTS $_WSREP_NEW_CLUSTER $_WSREP_START_POSITION (code=
      Process: 13086 ExecStartPre=/bin/sh -c [ ! -e /usr/bin/galera_recovery ] &amp;&amp; VAR= ||   VAR=`/usr/bin/gale
      Process: 13070 ExecStartPre=/bin/sh -c systemctl unset-environment _WSREP_START_POSITION (code=exited, s
      Process: 13033 ExecStartPre=/usr/bin/install -m 755 -o mysql -g root -d /var/run/mysqld (code=exited, st
     Main PID: 13247 (code=exited, status=1/FAILURE)
     Status: "MariaDB server is down"
     CGroup: /system.slice/mariadb.service
             └─3803 /usr/sbin/mysqld
  </code></pre>
  
  <blockquote>
    <p>sudo journalctl -xe</p>
  </blockquote>
  
  <pre><code>   Sep 14 03:35:51 ubuntu 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.
     Sep 14 03:35:51 ubuntu systemd[1]: mariadb.service: Unit entered failed state.
     Sep 14 03:35:51 ubuntu sudo[13566]: pam_unix(sudo:session): session closed for user root
     Sep 14 03:35:51 ubuntu systemd[1]: mariadb.service: Failed with result 'exit-code'.
     Sep 14 03:35:52 ubuntu sshd[13753]: Failed password for root from 123.183.209.136 port 38816 ssh2
     Sep 14 03:35:52 ubuntu sshd[13753]: Received disconnect from 123.183.209.136 port 38816:11:  [preauth]
     Sep 14 03:35:52 ubuntu sshd[13753]: Disconnected from 123.183.209.136 port 38816 [preauth]
     Sep 14 03:35:52 ubuntu sshd[13753]: PAM 1 more authentication failure; logname= uid=0 euid=0 tty=ssh ruser
     Sep 14 03:36:34 ubuntu sshd[13756]: Connection closed by 123.183.209.136 port 60477 [preauth]
     Sep 14 03:36:36 ubuntu postfix/pickup[12161]: 703AA5C0C5: uid=0 from=&lt;root&gt;
     Sep 14 03:36:36 ubuntu postfix/cleanup[12162]: 703AA5C0C5: message-id=&lt;20170914033636.703AA5C0C5@ubuntu.me
     Sep 14 03:36:36 ubuntu postfix/cleanup[12162]: warning: 703AA5C0C5: write queue file: No space left on dev
     Sep 14 03:36:36 ubuntu postfix/pickup[12161]: warning: maildrop/5152F5C0C4: error writing 703AA5C0C5: queu
     Sep 14 03:37:17 ubuntu sshd[13760]: Received disconnect from 123.183.209.136 port 25567:11:  [preauth]
     Sep 14 03:37:17 ubuntu sshd[13760]: Disconnected from 123.183.209.136 port 25567 [preauth]
     Sep 14 03:37:36 ubuntu postfix/pickup[12161]: 7764B5C0C5: uid=0 from=&lt;root&gt;
     Sep 14 03:37:36 ubuntu postfix/cleanup[12162]: 7764B5C0C5: message-id=&lt;20170914033736.7764B5C0C5@ubuntu.me
     Sep 14 03:37:36 ubuntu postfix/cleanup[12162]: warning: 7764B5C0C5: write queue file: No space left on dev
     Sep 14 03:37:36 ubuntu postfix/pickup[12161]: warning: maildrop/5152F5C0C4: error writing 7764B5C0C5: queu
     Sep 14 03:37:47 ubuntu sudo[13765]:      bob : TTY=pts/0 ; PWD=/home/bob ; USER=root ; COMMAND=/bin/journa
     Sep 14 03:37:47 ubuntu sudo[13765]: pam_unix(sudo:session): session opened for user root by bob(uid=0)
     lines 1238-1265/1265 (END)
  </code></pre>
  
  <p>I really don't want to lose my db.
  What should I do next?</p>
  
  <p>Many thanks</p>
  
  <p>this is what df gives me:</p>
  
  <pre><code>   Filesystem     1K-blocks     Used Available Use% Mounted on
     /dev/root       49362256 46854648         0 100% /
     devtmpfs         2019828        0   2019828   0% /dev
     tmpfs            2021768        0   2021768   0% /dev/shm
     tmpfs            2021768    17968   2003800   1% /run
     tmpfs               5120        0      5120   0% /run/lock
     tmpfs            2021768        0   2021768   0% /sys/fs/cgroup
     tmpfs             404356        0    404356   0% /run/user/1000
     tmpfs             404356        0    404356   0% /run/user/0
  </code></pre>