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Using telnet and it was pointing to a wrong address. Ping was directing to correct IP address

linux was solving hostname to an incorrect IP address when using telnet

root@linux:~ # telnet host24100
Trying 172.22.12.135…
telnet: connect to address 172.22.12.135: Connection refused

It was solving to the correct IP address when using ping

root@linux:~ # ping -c1 host24100
PING host099.setaoffice.com (172.22.84.143) 56(84) bytes of data.
64 bytes from host27100.setaoffice.com (172.22.84.143): icmp_seq=1 ttl=127 time=1.32 ms

— host099.setaoffice.com ping statistics —
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 1.321/1.321/1.321/0.000 ms

I’ve restarted nscd service

root@linux:~ # service nscd status
Checking for Name Service Cache Daemon: running

root@linux:~ # service nscd stop
Shutting down Name Service Cache Daemon done

root@linux:~ # service nscd start
Starting Name Service Cache Daemon done

After the restart, it started to point to the correct IP address

root@linux:~ # telnet host24100 24100
Trying 172.22.84.143…
Connected to host24100.
Escape character is ‘^]’.
0G^]
telnet> quit
Connection closed.

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Booting Linux into single user or emergency mode

For Red Hat Enterprise Linux 6
Single-User Mode
Single-user mode provides a Linux environment for a single user that allows you to recover your system from problems that cannot be resolved in networked multi-user environment. You do not need an external boot device to be able to boot into single-user mode, and you can switch into it directly while the system is running.

At the GRUB boot screen, press any key to enter the GRUB interactive menu.
Select Red Hat Enterprise Linux with the version of the kernel that you want to boot and press the a to append the line.
Type single as a separate word at the end of the line and press Enter to exit GRUB edit mode. Alternatively, you can type 1 instead of single.

Emergency Mode
Emergency mode, provides the minimal bootable environment and allows you to repair your system even in situations when rescue mode is unavailable. In emergency mode, the system mounts only the root file system, and it is mounted as read-only. Also, the system does not activate any network interfaces and only a minimum of the essential services are set up. The system does not load any init scripts, therefore you can still mount file systems to recover data that would be lost during a re-installation if init is corrupted or not working.

At the GRUB boot screen, press any key to enter the GRUB interactive menu.
Select Red Hat Enterprise Linux with the version of the kernel that you want to boot and press the a to append the line.
Type emergency as a separate word at the end of the line and press Enter to exit GRUB edit mode.

UXMON: The selfclean UXMON module has failed, please check reason on server

Node : solaris.setaoffice.com
Node Type : Sun SPARC (HTTPS)
Severity : warning
OM Server Time: 2019-05-02 02:00:04
Message : UXMON: The selfclean UXMON module has failed, please check reason
Msg Group : OS
Application : uxmon
Object : selfclean
Event Type :
not_found

Instance Name :
not_found

Instruction : No
EventDataSource :

iLO 4 Embedded Flash/SD-CARD Embedded media manager failed media attach

iLO 4 was presenting the message: Embedded Flash/SD-CARD Embedded media manager failed media attach.

I’ve updated iLO 4 to v 2.70 and then performed the following procedure

Advisory: (Revision) HPE Integrated Lights-Out 4 (iLO 4) – How to Format the NAND Used to Store AHS logs, OneView Profiles, and Intelligent Provisioning

Created a file Force_Format.xml

root@linux:~ # vi Force_Format.xml
<RIBCL VERSION=”2.0″>
<LOGIN USER_LOGIN=”adminname” PASSWORD=”password”>
<RIB_INFO MODE=”write”>
<FORCE_FORMAT VALUE=”all”/>
</RIB_INFO>
</LOGIN>
</RIBCL>

Run hponcfg -f Force_Format.xml

root@linux:~ # hponcfg -f Force_Format.xml -l log.txt
HP Lights-Out Online Configuration utility
Version 4.6.0 Date 09/28/2015 (c) Hewlett-Packard Company, 2015
Firmware Revision = 2.70 Device type = iLO 4 Driver name = hpilo
Script succeeded

Then I reset ILO through the web interface

smbclient receiving error message: protocol negotiation failed: NT_STATUS_CONNECTION_DISCONNECTED

I have a Red Hat Enterprise Linux 7.5 server that is not connecting to a Windows share

root@linux:~ # cat /etc/*release
NAME=”Red Hat Enterprise Linux Server”
VERSION=”7.5 (Maipo)”
ID=”rhel”
ID_LIKE=”fedora”
VARIANT=”Server”
VARIANT_ID=”server”
VERSION_ID=”7.5″
PRETTY_NAME=”Red Hat Enterprise Linux”
ANSI_COLOR=”0;31″
CPE_NAME=”cpe:/o:redhat:enterprise_linux:7.5:GA:server”
HOME_URL=”https://www.redhat.com/&#8221;
BUG_REPORT_URL=”https://bugzilla.redhat.com/&#8221;

REDHAT_BUGZILLA_PRODUCT=”Red Hat Enterprise Linux 7″
REDHAT_BUGZILLA_PRODUCT_VERSION=7.5
REDHAT_SUPPORT_PRODUCT=”Red Hat Enterprise Linux”
REDHAT_SUPPORT_PRODUCT_VERSION=”7.5″
Red Hat Enterprise Linux Server release 7.5 (Maipo)
Red Hat Enterprise Linux Server release 7.5 (Maipo)

samba rebased to version 4.6.2

To improve security, the NT LAN manager version 1 (NTLMv1) protocol is now disabled by default. If you require the insecure NTLMv1 protocol, set the ntlm auth parameter in the /etc/samba/smb.conf file to yes.

The storage was upgraded so my RHEL 7.5 server is the client trying to connect to the Windows share. It is showing the message protocol negotiation failed: NT_STATUS_CONNECTION_DISCONNECTED

root@linux:~ # smbclient //storageserver/PUBLICO -U “setaoffice/username%PASSWORD” -c ‘prompt; cd CC_EFC_Inbound/Logs; mget *.log’
protocol negotiation failed: NT_STATUS_CONNECTION_DISCONNECTED

To solve the problem, I had to add -m SMB2 or -m SMB3 to the smbclient

root@linux:~ # smbclient //storageserver/PUBLICO -U “setaoffice/username%PASSWORD” -m SMB2 -c ‘prompt; cd CC_EFC_Inbound/Logs; mget *.log’
Kinit for username@SETAOFFICE to access storageserver failed: Cannot find KDC for requested realm
session setup failed: NT_STATUS_WRONG_PASSWORD

Control-M: The SMTP server did not respond in a timely manner. Please check the Port Number and the SMTP Server (Relay) Name.

Control-M application

Simple Mail Transfer Protocol Parameters Menu
———————————————-

Select one of the following options:

1 – SMTP Server (Relay) Name : mailBR.setaoffice.com
2 – Sender Email : controlm@setaoffice.com
3 – Port Number : 25
4 – Sender Friendly Name : ControlM – Production
5 – Reply-To Email : productioncontrolm@setaoffice.com
6 – Test SMTP Settings

s – Save Parameters

q – Quit

Enter option number —> [q]:6

Testing SMTP Settings…

The SMTP server did not respond in a timely manner.
Please check the Port Number and the SMTP Server (Relay) Name.

Press Enter to continue

Host mailBR.setaoffice.com was being resolved to a different IP address because it was in /etc/hosts file of the server

SAP return code XXX

R49 Basis System: Communication error, CPIC return code 020, SAP return code 223
223 – Network read error

R49 Basis System: Communication error, CPIC return code 017, SAP return code 236
236 – No connection to the gateway

R49 Basis System: Communication error, CPIC return code 020, SAP return code 456
456 – Timeout when establishing connection

R49 Basis System: Communication error, CPIC return code 019, SAP return code 728
728 – Conversation ID not found

RHEL 6 server receiving error mounting CIFS (Windows) share – mount error(112): Host is down

When mounting a CIFS (Windows) share, I’m receiving an error saying the host is down

root@linux:~ # mount /mnt/test
mount error(112): Host is down
Refer to the mount.cifs(8) manual page (e.g. man mount.cifs)

This is the share in /etc/fstab

root@linux:~ # cat /etc/fstab
//10.0.0.1/CIFS$ /mnt/test cifs _netdev,user=appuser,pass=1234,uid=21376,gid=252,file_mode=0775,dir_mode=0775,domain=windows

I’m running a RHEL 6.9 server

root@linux:~ # cat /etc/*release
LSB_VERSION=base-4.0-amd64:base-4.0-noarch:core-4.0-amd64:core-4.0-noarch:graphics-4.0-amd64:graphics-4.0-noarch:printing-4.0-amd64:printing-4.0-noarch
Red Hat Enterprise Linux Server release 6.9 (Santiago)
Red Hat Enterprise Linux Server release 6.9 (Santiago)

This problem happened because the storage was upgraded and it is using SMB2. You need to have at least kernel 3.7 to have support for SMB2
SMB shares fail to mount with the SMB2 protocol

insserv: warning: script missing LSB tags and overrides | insserv: Stopping depends on and therefore on system facility `$all’ which can not be true!

When trying to enable xinetd to start on boot, insserv was throwing error message and not enabling it.

root@linux:~ # chkconfig –list xinetd
xinetd 0:off 1:off 2:off 3:off 4:off 5:off 6:off

root@linux:~ # chkconfig xinetd on
insserv: warning: script ‘K02OVTrcSrv’ missing LSB tags and overrides
insserv: warning: script ‘OVTrcSrv’ missing LSB tags and overrides
insserv: warning: script ‘esmrc’ missing LSB tags and overrides
insserv: Default-Start undefined, assuming default start runlevel(s) for script `esmrc’
insserv: There is a loop between service OVCtrl and esmrc if stopped
insserv: loop involving service esmrc at depth 2
insserv: loop involving service OVCtrl at depth 1
insserv: Stopping esmrc depends on OVCtrl and therefore on system facility `$all’ which can not be true!
insserv: exiting now without changing boot order!
/sbin/insserv failed, exit code 1

https://unix.stackexchange.com/questions/289667/unable-to-install-anything-using-apt-get-because-of-insserv

First of all, the problem is that you are stuck at the boot sequencing.

The boot sequencing method is decided during installation or upgrades. If there are no loops in the dependencies declared by the LSB headers of all installed init.d scripts and no obsolete scripts, the system is converted to dependency based boot sequence.

We have to check for

1. Loop in dependencies: Occurs when >
• There are missing LSB tags in some scripts or error in LSB tags like missing Required-Start: or Required-Stop: tags

• Some scripts depend on other scripts which depend on the system facility $all which cannot be true. Because the scripts depending on $all is loaded last at starting. Since it loads last, nothing can depend on it. Hence, messes up the dependency based boot sequence.

2. Obsolete scripts: Occur when

• Some packages being upgraded to newer versions which may not use a script in /etc/init.d/ and the maintainer may have missed the code to remove the old script. Not our mistake.

I edited file /etc/init.d/esmrc and added a LSB header after #!/bin/sh

root@linux:~ # vi /etc/init.d/esmrc
#!/bin/sh
### BEGIN INIT INFO
# Provides: esmrc
# Required-Start:
# Should-Start: $remote_fs $network $syslog
# Required-Stop:
# Should-Stop: $remote_fs $network $syslog
# Default-Start: 2 3 5
# Default-Stop: 0 1 4 6
# Short-Description : Enterprise Security Manager
# Description : Enterprise Security Manager (ESM) allows a computer to be
# monitored for compliance with security policy.
### END INIT INFO
#
# For HP-UX version 10.xx platforms the above line must be changed to
# ‘/sbin/sh’ by esmsetup and by the tune-up pack.
#
#*************************************************************************
###############################################################################
# Enterprise Security Manager (r)
###############################################################################

Linux LVM: File-based locking initialisation failed

Running a lvm command and you encounter the message File-based locking initialisation failed means that the filesystem is read-only

root@linux:~ # pvs
File-based locking initialisation failed

The directory /var/lock/lvm must be writable. So you have a /var or / filesystem read-only.

You can try to remount it as read-write or reboot the server

mount -o remount,rw /
reboot -d -n -f

Source: Running an LVM command returns “File-based locking initialisation failed” or “Locking type 1 initialisation failed”

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