Oracle与/etc/hosts关系很暧昧啊~

昨天处理了一个小case，后来发现不知道哪位亲爱的朋友修改了/etc/hosts文件，导致数据库趴下了，记录一下

[root@padb ~]# su - oracle$$ps -ef|grep ora_oracle    5874  5847  0 11:35 pts/3    00:00:00 grep ora_$lsnrctl statusLSNRCTL for Linux: Version 11.2.0.3.0 - Production on 12-JUL-2018 11:35:33Copyright (c) 1991, 2011, Oracle.  All rights reserved.Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=localhost)(PORT=1521)))###########监听卡在这里了####################$ps -ef|grep lsnroracle    5808  5757  0 11:34 pts/1    00:00:00 lsnrctl startoracle    5810     1 99 11:34 ?        00:01:36 /u01/app/oracle/product/11.2.0/dbhome_1/bin/tnslsnr LISTENER -inheritoracle    5877  5847  0 11:35 pts/3    00:00:00 grep lsnr##############进程在$kill -9 5810$ps -ef|grep lsnroracle    5879  5847  0 11:35 pts/3    00:00:00 grep lsnr##############kill 进程 $sqlplus / as sysdbaSQL*Plus: Release 11.2.0.3.0 Production on Thu Jul 12 11:35:56 2018Copyright (c) 1982, 2011, Oracle.  All rights reserved.Connected.SQL> ###############很诡异的一个状态，竟然connected了##############查看日志$uptime 11:36:27 up 50 min,  4 users,  load average: 0.42, 0.33, 0.47$adrciADRCI: Release 11.2.0.3.0 - Production on Thu Jul 12 11:36:35 2018Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.ADR base = "/u01/app/oracle"adrci> show alertChoose the alert log from the following homes to view:1: diag/clients/user_oracle/host_61728193_802: diag/rdbms/padb/padb3: diag/tnslsnr/localhost/listener4: diag/tnslsnr/padb/listenerQ: to quitPlease select option: 2Output the results to file: /tmp/alert_5886_14061_padb_1.ado2017-12-05 18:40:29.250000 +08:00Starting ORACLE instance (normal)****************** Large Pages Information *****************Total Shared Global Region in Large Pages = 0 KB (0%)Large Pages used by this instance: 0 (0 KB)Large Pages unused system wide = 0 (0 KB) (alloc incr 64 MB)Large Pages configured system wide = 0 (0 KB)Large Page size = 2048 KBRECOMMENDATION:  Total Shared Global Region size is 24 GB. For optimal performance,  prior to the next instance restart increase the number  of unused Large Pages by atleast 12097 2048 KB Large Pages (24 GB)  system wide to get 100% of the Shared  Global Region allocated with Large pages***********************************************************LICENSE_MAX_SESSION = 0LICENSE_SESSIONS_WARNING = 0Shared memory segment for instance monitoring createdPicked latch-free SCN scheme 3Machine:x86_64VM name:VMWare Version: 6home_1/dbs/spfilepadb.oraSystem parameters with non-default values:  processes                = 500  sessions                 = 780  sga_target               = 24192M  control_files            = "/u01/app/oracle/padb/control01.ctl"  control_files            = "/u01/app/oracle/padb/control02.ctl"  db_block_size            = 8192  compatible               = "11.2.0.0.0"  undo_tablespace          = "UNDOTBS1"  remote_login_passwordfile= "EXCLUSIVE"  db_domain                = ""  dispatchers              = "(PROTOCOL=TCP) (SERVICE=padbXDB)"  audit_file_dest          = "/u01/app/oracle/admin/padb/adump"  audit_trail              = "DB"  db_name                  = "padb"  open_cursors             = 300  pga_aggregate_target     = 8053M  diagnostic_dest          = "/u01/app/oracle"USER (ospid: 5117): terminating the instance due to error 119ORACLE_HOME = /u01/app/oracle/product/11.2.0/dbhome_1System name:LinuxNode name:padbRelease:2.6.32-573.el6.x86_64Version:#1 SMP Wed Jul 1 18:23:37 EDT 2015Machine:x86_64VM name:VMWare Version: 6Using parameter settings in server-side spfile /u01/app/oracle/product/11.2.0/dbbhome_1/dbs/spfilepadb.oraSystem parameters with non-default values:  processes                = 500  sessions                 = 780  sga_target               = 24192M  control_files            = "/u01/app/oracle/padb/control01.ctl"  control_files            = "/u01/app/oracle/padb/control02.ctl"  db_block_size            = 8192  compatible               = "11.2.0.0.0"  undo_tablespace          = "UNDOTBS1"  remote_login_passwordfile= "EXCLUSIVE"  db_domain                = ""  dispatchers              = "(PROTOCOL=TCP) (SERVICE=padbXDB)"  audit_file_dest          = "/u01/app/oracle/admin/padb/adump"  audit_trail              = "DB"  db_name                  = "padb"  open_cursors             = 300  pga_aggregate_target     = 8053M  diagnostic_dest          = "/u01/app/oracle"USER (ospid: 5117): terminating the instance due to error 119  remote_login_passwordfile= "EXCLUSIVE"  db_domain                = ""  dispatchers              = "(PROTOCOL=TCP) (SERVICE=padbXDB)"  audit_file_dest          = "/u01/app/oracle/admin/padb/adump"  audit_trail              = "DB"  db_name                  = "padb"  open_cursors             = 300  pga_aggregate_target     = 8053M  diagnostic_dest          = "/u01/app/oracle"2018-07-12 09:45:28.043000 +08:00USER (ospid: 18388): terminating the instance due to error 119Instance terminated by USER, pid = 18388                           ############实例异常终止了2018-07-12 09:47:53.701000 +08:00Starting ORACLE instance (normal)"/tmp/alert_5886_14061_padb_1.ado" 13117L, 632251C written$df -hFilesystem            Size  Used Avail Use% Mounted on/dev/mapper/VolGroup-lv_root                      627G  512G   84G  86% /tmpfs                  32G   72K   32G   1% /dev/shm/dev/sda1             477M   42M  410M  10% /boot$$sqlplus / as sysdbaSQL*Plus: Release 11.2.0.3.0 Production on Thu Jul 12 11:47:10 2018Copyright (c) 1982, 2011, Oracle.  All rights reserved.Connected.SQL> startupORA-00119: invalid specification for system parameter LOCAL_LISTENERORA-00130: invalid listener address '(ADDRESS=(PROTOCOL=TCP)(HOST=padb)(PORT=1521))'SQL> ##########第一意识ping了一下主机名$ping padbping: unknown host padb$ping padbping: unknown host padb$hostnamepadb$more /etc/hosts127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4::1         localhost localhost.localdomain localhost6 localhost6.localdomain6padb  10.18.0.84    ##到这里，只能无语了,外加18个点点点，这是啥啊！！！！$ping padbping: unknown host padb$exitlogout####修改host文件[root@padb ~]# vi /etc/hosts127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4::1         localhost localhost.localdomain localhost6 localhost6.localdomain610.18.0.84  padb  "/etc/hosts" 3L, 175C written[root@padb ~]# [root@padb ~]# [root@padb ~]# ping padbPING padb (10.18.0.84) 56(84) bytes of data.64 bytes from padb (10.18.0.84): icmp_seq=1 ttl=64 time=0.029 ms64 bytes from padb (10.18.0.84): icmp_seq=2 ttl=64 time=0.021 ms^C--- padb ping statistics ---2 packets transmitted, 2 received, 0% packet loss, time 1804msrtt min/avg/max/mdev = 0.021/0.025/0.029/0.004 ms[root@padb ~]# Refer to the SQL*Plus User's Guide and Reference for more information.$sqlplus / as sysdbaSQL*Plus: Release 11.2.0.3.0 Production on Thu Jul 12 12:01:43 2018Copyright (c) 1982, 2011, Oracle.  All rights reserved.Connected to an idle instance.SQL> startupORACLE instance started.Total System Global Area 2.5254E+10 bytesFixed Size                  2240096 bytesVariable Size            3221225888 bytesDatabase Buffers         2.2012E+10 bytesRedo Buffers               18718720 bytesDatabase mounted.Database opened.SQL> exit