Can’t edit /etc/resolv.conf with root account problem.

  • A file is set with ‘i‘ attribute, cannot be modified (immutable). Means no renaming, no symbolic link creation, no execution, no writable, only superuser can unset the attribute.
  •  we use the + sign and to unset use the – sign with the chattr command.
    + : Adds the attribute to the existing attribute of the files.
    – : Removes the attribute to the existing attribute of the files.
    = : Keep the existing attributes that the files have.
vi /etc/resolv.conf 
/etc/resolv.conf" [readonly] 12L, 301C 
[root@rhel6 ~]# lsattr /etc/resolv.conf
----i--------e- /etc/resolv.conf
[root@rhel6 ~]# chattr -i /etc/resolv.conf
[root@rhel6 ~]# lsattr /etc/resolv.conf
-------------e- /etc/resolv.conf
[root@rhel6 ~]# vi /etc/resolv.conf
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-bash: /bin/rm: Argument list too long wile removing files

Problem:

I have a directoy in linux that has several hundred thousand files, and is about 8.2 Gb. I attempted to clear out the directory using ‘rm -rf *aud’, and got the following error:

Oracle audit files:

[oracle@drexa01dbadm01 rdbms]$ du -sh audit
8.2G audit
[oracle@drexa01dbadm01 rdbms]$ cd audit/
[oracle@drexa01dbadm01 audit]$pwd
/u01/app/oracle/product/12.1.0.2/dbhome_1/rdbms/audit
[oracle@drexa01dbadm01 audit]$ rm -rf *aud
-bash: /bin/rm: Argument list too long
[oracle@drexa01dbadm01 audit]$

Solution:

[root@drexa01dbadm01 audit]# find . -name '*aud' | xargs rm -v
removed `./opum_ora_5570_20170419113001272611143795.aud'
removed `./opum_ora_19087_20170825213720316402143795.aud'
removed `./opum_ora_24477_20170215033002283227143795.aud'
removed `./opum_ora_7691_20160815080001986930143795.aud'
removed `./opum_ora_16653_20160907043002231684143795.aud'
removed `./opum_ora_13406_20170127234157760483143795.aud'
removed `./opum_ora_20966_20160830140953226189143795.aud'
removed `./opum_ora_32328_20160302052636008652143795.aud'
removed `./opum_ora_8918_20170924193849158242143795.aud'
removed `./opum_ora_3496_20160915031853572953143795.aud'
removed `./opum_ora_6372_20161020181850094006143795.aud'
removed `./opum_ora_14855_20161014233431338219143795.aud'
removed `./opum_ora_3543_20160320162656730084143795.aud'
removed `./opum_ora_507_20171004204104885761143795.aud'
removed `./opum_ora_28535_20160510060437060235143795.aud'
removed `./opum_ora_12919_20170501052812370394143795.aud'
removed `./opum_ora_19556_20161209185701631815143795.aud'
removed `./opum_ora_4558_20170821004123546569143795.aud'
removed `./opum_ora_12780_20170113235941423540143795.aud'
removed `./opum_ora_7448_20160602072824080487143795.aud'
removed `./opum_ora_25740_20160704060001516869143795.aud'
removed `./opum_ora_18222_20170211181055180098143795.aud'
removed `./opum_ora_14988_20160619075753542821143795.aud'
removed `./opum_ora_18060_20170510231755910407143795.aud'
removed `./opum_ora_4974_20160904032946872225143795.aud'
removed `./opum_ora_22492_20160810164246080476143795.aud'
removed `./opum_ora_30220_20160730184335973711143795.aud'
removed `./opum_ora_9281_20160601050646550905143795.aud'
removed `./opum_ora_23802_20161007002846100802143795.aud'
removed `./opum_ora_31124_20170722151749240758143795.aud'
removed `./opum_ora_19994_20160603044311483365143795.aud'
removed `./opum_ora_12052_20160228214028001728143795.aud'
removed `./opum_ora_15291_20170914184724665451143795.aud'
removed `./opum_ora_22103_20160603225229269785143795.aud'
removed `./opum_ora_16853_20170731031019341399143795.aud'
removed `./opum_ora_17237_20170418113002372693143795.aud'
removed `./opum_ora_6563_20161224000002747653143795.aud'
removed `./opum_ora_25523_20170623172237509923143795.aud'
removed `./opum_ora_31895_20160806180001664608143795.aud'

 

 

 

Permissions on the password database may be too restrictive. su: incorrect password Problem

Environment

  • SLES for SAP Applications 11.4 (x86_64)
  • SUSE Linux Enterprise Server 11 (x86_64)

Issue

  • Permissions on the password database may be too restrictive.
    su: incorrect password

Resolution

  • Re-create the oragrid user.

agrcpgd1:oraegp 54> su – oragrid
Password:
Permissions on the password database may be too restrictive.
su: incorrect password

  • check user id and group id 

agrcpgd1:~ # cat /etc/passwd| grep oragrid
oragrid:x:507:503:Grid Admin:/home/oragrid:/bin/bash
agrcpgd1:~ # id oragrid
uid=507(oragrid) gid=503(dba) groups=503(dba)

  • Remove oragrid user without -r option.(-r option:To remove the user’s home directory and mail spool )

agrcpgd1:~ # userdel oragrid
no crontab for oragrid

  • Add user with userid and groupid.

agrcpgd1:~ # useradd -u 507 -g 503 -c “Grid Admin” -d /home/oragrid oragrid
agrcpgd1:~ # passwd oragrid
Changing password for oragrid.
New Password:
Reenter New Password:
Password changed.

agrcpgd1:oraegp 51> su – oragrid
Password:
oragrid@agrcpgd1:~>

Oracle Enterprise Manager Cloud Control 12c Release on EXADATA

Please execute the below steps to restart the agent on Exadata;

Commands to be executed  with “orarom” user;

/opt/OracleHomes/agent_home/agent_inst/bin/emctl status agent 
/opt/OracleHomes/agent_home/agent_inst/bin/emctl stop agent 
/opt/OracleHomes/agent_home/agent_inst/bin/emctl start agent 

Example;

[root@exa01dbadm02 ~]# su – orarom
[orarom@exa01dbadm02 ~]$ /opt/OracleHomes/agent_home/agent_inst/bin/emctl status agent
Oracle Enterprise Manager Cloud Control 12c Release 4
Copyright (c) 1996, 2014 Oracle Corporation. All rights reserved.
—————————————————————
Agent is Not Running
[orarom@exa01dbadm02 ~]$ /opt/OracleHomes/agent_home/agent_inst/bin/emctl stop agent
Oracle Enterprise Manager Cloud Control 12c Release 4
Copyright (c) 1996, 2014 Oracle Corporation. All rights reserved.
Agent is Not Running
[orarom@exa01dbadm02 ~]$ /opt/OracleHomes/agent_home/agent_inst/bin/emctl start agent
Oracle Enterprise Manager Cloud Control 12c Release 4
Copyright (c) 1996, 2014 Oracle Corporation. All rights reserved.
Starting agent ……………………………………………………. ……………………… started.
[orarom@exa01dbadm02 ~]$

EXADATA: How to configure ssh for current user on a list of nodes?

APPLIES TO:

Oracle Exadata Storage Server Software – Version 11.2.1.2.0 and later.

GOAL

Customer needs steps to configure ssh on exadata.

SOLUTION

Run the following on a db node, and follow the prompts.
/opt/oracle.SupportTools/onecommand/setssh-Linux.sh -h /opt.oracle.SupportTools/onecommand/all_nodelist_group
This will configure passwordless ssh for current user for the list of nodes specified in all_nodelist_group.

 

If the utility is missing, it can be extracted from a current download of the onecommand utility

see Document : 888828.1 – Exadata Database Machine and Exadata Storage Server Supported Versions

 

/opt.oracle.SupportTools/onecommand/all_nodelist_group —you may need to create a file with the host entries for which you need SSH.

Example;

IBSWITCH_GROUP –Keep the ibswitches in that file and pass in that command.

[root@exa01dbadm01 ~]# cd /opt/oracle.SupportTools/onecommand/
[root@exa01dbadm01 onecommand]# vi IBSWITCH_GROUP
exa01sw-iba01
exa01sw-ibb01

[root@exa01dbadm01 onecommand]#chmod 775  IBSWITCH_GROUP 

[root@exa01dbadm01 onecommand]# ./setssh-Linux.sh -s -p  PassWord -n N -h IBSWITCH_GROUP
[root@exa01dbadm01 onecommand]# cat IBSWITCH_GROUP
exa01sw-iba01
exa01sw-ibb01
[root@exa01dbadm01 onecommand]# ssh exa01sw-iba01
Last login: Sat Oct 14 15:39:56 2017 from exa01dbadm01.omsan.com.tr
You are now logged in to the root shell.
It is recommended to use ILOM shell instead of root shell.
All usage should be restricted to documented commands and documented
config files.
To view the list of documented commands, use “help” at linux prompt.
[root@exa01sw-iba01 ~]#

For different user from root (for example oracle user)

EXADATA passwordless SSH login not working for oracle user

i. Login to the oracle account:
# su – oracle

ii. Create a dcli group file listing the nodes in the Oracle Cluster.

iii. Run the setup ssh script (this assumes the oracle password on all servers in the dbs_group list is set to “welcome””
$./setssh-Linux.sh -s -p welcome1 -n N -h dbs_group

Source:Oracle support note(Doc ID 1923785.1)

 

How can I check the port status of my fibre channel HBA?

Environment

  • Red Hat Enterprise Linux 5
  • Red Hat Enterprise Linux 6

Issue

  • Need to check the port status of my fibre channel HBA

Resolution

  • The state of the port can be checked within the /sys/class directory either via
$ systool -c fc_host -v    from sysfsutils package
Class = "fc_host"

  Class Device = "host10"
  Class Device path = "/sys/class/fc_host/host10"
    fabric_name         = "0x200000e08b8068ae"
    issue_lip           = 
    node_name           = "0x200000e08b8068ae"
    port_id             = "0x000000"
    port_name           = "0x210000e08b8068ae"
    port_state          = "Linkdown"
    port_type           = "Unknown"
    speed               = "unknown"
    supported_classes   = "Class 3"
    supported_speeds    = "1 Gbit, 2 Gbit, 4 Gbit"
    symbolic_name       = "QLE2460 FW:v5.06.03 DVR:v8.03.07.15.05.09-k"
    system_hostname     = ""
    tgtid_bind_type     = "wwpn (World Wide Port Name)"
    uevent              = 

    Device = "host10"
    Device path = "/sys/devices/pci0000:00/0000:00:04.0/0000:08:00.0/host10"
      optrom_ctl          = 
      reset               = 
      uevent              = 
:

or if sysfsutils package is not installed

[root@axx /]# grep -v "zZzZ" -H /sys/class/fc_host/host*/port_state
/sys/class/fc_host/host0/port_state:Linkdown
/sys/class/fc_host/host1/port_state:Linkdown