几天前（8月18日），一位朋友意外地在他的pipe理面板（VPS主机是OVH）重新启动了他的VPS。 问题是…它从来没有重新启动。 他在几个月内没有做任何改变，他的VPS正在CentOS 6上运行一个Plesk面板。
救援启动（从Live CD启动）运行良好。 我可以挂载分区并查看所有数据。 我试图在/var/log寻找提示，但自8月18日以来没有logging 。 我今天没有尝试重新启动它的日志。
tail -n 20 /var/log/messages ：
Aug 18 11:28:21 vpsXXXXXX proftpd[11413]: XXX.XXX.XXX.XXX (YYY.YYY.YYY.YYY[YYY.YYY.YYY.YYY]) - FTP session opened. Aug 18 11:29:22 vpsXXXXXX proftpd[11413]: XXX.XXX.XXX.XXX (YYY.YYY.YYY.YYY[YYY.YYY.YYY.YYY]) - FTP session closed. Aug 18 11:29:22 vpsXXXXXX xinetd[1020]: EXIT: ftp status=0 pid=11413 duration=61(sec) Aug 18 11:38:09 vpsXXXXXX init: tty (/dev/tty1) main process (2901) killed by TERM signal Aug 18 11:38:09 vpsXXXXXX init: serial (ttyS0) main process (2902) killed by TERM signal Aug 18 11:38:11 vpsXXXXXX xinetd[1020]: Exiting... Aug 18 11:38:11 vpsXXXXXX acpid: exiting Aug 18 11:38:11 vpsXXXXXX init: Disconnected from system bus Aug 18 11:38:11 vpsXXXXXX console-kit-daemon[30927]: WARNING: no sender#012 Aug 18 11:38:11 vpsXXXXXX named[376]: received control channel command 'stop' Aug 18 11:38:11 vpsXXXXXX named[376]: shutting down: flushing changes Aug 18 11:38:11 vpsXXXXXX named[376]: stopping command channel on 127.0.0.1#953 Aug 18 11:38:11 vpsXXXXXX named[376]: no longer listening on 127.0.0.1#53 Aug 18 11:38:11 vpsXXXXXX named[376]: no longer listening on XXX.XXX.XXX.XXX#53 Aug 18 11:38:11 vpsXXXXXX named[376]: exiting Aug 18 11:38:11 vpsXXXXXX auditd[817]: The audit daemon is exiting. Aug 18 11:38:11 vpsXXXXXX kernel: type=1305 audit(1503049091.989:89): audit_pid=0 old=817 auid=4294967295 ses=4294967295 res=1 Aug 18 11:38:12 vpsXXXXXX kernel: type=1305 audit(1503049092.089:90): audit_enabled=0 old=1 auid=4294967295 ses=4294967295 res=1 Aug 18 11:38:12 vpsXXXXXX kernel: Kernel logging (proc) stopped. Aug 18 11:38:12 vpsXXXXXX rsyslogd: [origin software="rsyslogd" swVersion="5.8.10" x-pid="847" x-info="http://www.rsyslog.com"] exiting on signal 15.
cat /var/log/boot.log输出：
Welcome to CentOS Starting udev: udevd[306]: can not read '/etc/udev/rules.d/75-persistent-net-generator.rules' udevd[306]: can not read '/etc/udev/rules.d/75-persistent-net-generator.rules' [ OK ] Setting hostname vpsXXXXXX.ovh.net: [ OK ] Checking filesystems Checking all file systems. [/sbin/fsck.ext4 (1) -- /] fsck.ext4 -a /dev/vda1 /dev/vda1: clean, 244942/1638400 files, 6238128/6553344 blocks [ OK ] Remounting root filesystem in read-write mode: [ OK ] Mounting local filesystems: [ OK ] ln: creating symbolic link `/dev/root': File exists Enabling /etc/fstab swaps: [ OK ] Entering non-interactive startup ip6tables: Applying firewall rules: [ OK ] iptables: Applying firewall rules: [ OK ] Bringing up loopback interface: [ OK ] Bringing up interface eth0: Determining IP information for eth0... done. [ OK ] Starting auditd: [ OK ] Starting portreserve: [ OK ] Starting system logger: [ OK ] Starting Dr.Web drwebd... Dr.Web (R) daemon for Linux/Plesk Edition v6.0.2.1 Copyright (c) Igor Daniloff, 1992-2017 Doctor Web, Moscow, Russia Support service: http://support.drweb.com To purchase: http://buy.drweb.com Key file: /opt/drweb/drweb32.key - Key file was not found! (No such file or directory) A path to a valid license key file was not specified. Plesk authorization failed: HTTP request error [7] Error: Plesk Software not running. Starting kdump:[ OK ] Starting system message bus: [ OK ] Mounting filesystems: [ OK ] Starting acpi daemon: [ OK ] Retrigger failed udev events[ OK ] Starting sshd: [ OK ] Starting xinetd: [ OK ] Starting Courier IMAP authentication daemon: [ OK ] Starting Courier IMAP server: [ OK ] Starting Courier IMAP server with SSL/TLS support: [ OK ] Starting Courier POP3 server: [ OK ] Starting Courier POP3 server with SSL/TLS support: [ OK ] Starting psa-pc-remote: [ OK ] Starting php-fpm: [18-Aug-2017 11:16:04] WARNING: Nothing matches the include pattern '/opt/plesk/php/5.6/etc/php-fpm.d/*.conf' from /opt/plesk/php/5.6/etc/php-fpm.conf at line 119. [18-Aug-2017 11:16:04] ERROR: No pool defined. at least one pool section must be specified in config file [18-Aug-2017 11:16:04] ERROR: failed to post process the configuration [18-Aug-2017 11:16:04] ERROR: FPM initialization failed [FAILED] Starting psa... Starting sw-engine-fpm: [ OK ] done Starting xinetd service... done Starting sw-cp-server service... done Starting mysqld service... failed Trying to connect to MySQL... Failed to connect to MySQL: ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2) Trying to start service mysqld... mysqld dead but pid file exists Timeout error occurred trying to start MySQL Daemon. Starting mysqld: [FAILED] WARNING! Some problems are found during start(see log file: /var/log/plesk/install/plesk_12.0.18_reset_instance_data.log) Continue... Trying to start service mysqld... mysqld dead but pid file exists Timeout error occurred trying to start MySQL Daemon. Starting mysqld: [FAILED] WARNING! Some problems are found during start(see log file: /var/log/plesk/install/plesk_12.0.18_reset_instance_data.log) Continue... Trying to establish test connection... ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2) ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2) ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (111) ERROR 2013 (HY000): Lost connection to MySQL server at 'reading initial communication packet', system error: 104 failed ERROR while trying to establish test connection Check the error reason(see log file: /var/log/plesk/install/plesk_12.0.18_reset_instance_data.log), fix and try again Starting named service... done Starting postgresql service... not installed Starting spamassassin service... not installed Plesk: Starting Mail Server... done Starting psa... Starting sw-engine-fpm: done Starting sw-engine-fpm: Starting nginx: [ OK ] Starting crond: [ OK ] initctl: Event failed
在这种情况下，当机器启动时，您无法在屏幕上看到潜在的错误，您如何诊断和解决这些问题？