RHEL7: rc.local service not starting

It’s very common to automate application startup in rc.local on Linux systems.

Was testing Red Hat 7.2 (Maipo), and found that apps was’t started.

Found this on some Red Hat blog: 

Systemd is a system and service manager for Linux operating systems. It is designed to be backwards compatible with SysV init scripts, and provides a number of features such as parallel startup of system services at boot time, on-demand activation of daemons, support for system state snapshots, or dependency-based service control logic. In Red Hat Enterprise Linux 7, systemd replaces Upstart as the default init system.”

On default /etc/rc.local comes useful info:

#!/bin/bash
# THIS FILE IS ADDED FOR COMPATIBILITY PURPOSES
#
# It is highly advisable to create own systemd services or udev rules
# to run scripts during boot instead of using this file.
#
# In contrast to previous versions due to parallel execution during boot
# this script will NOT be run after all other services.
#
# Please note that you must run ‘chmod +x /etc/rc.d/rc.local’ to ensure
# that this script will be executed during boot.

touch /var/lock/subsys/local

Then, this ‘chmod’ turns rc.local enable during system startup.

 

To familiarize this new feature:

[root@somesystem~]# systemctl status rc-local
● rc-local.service - /etc/rc.d/rc.local Compatibility
Loaded: loaded (/usr/lib/systemd/system/rc-local.service; static; vendor preset: disabled)
Active: active (running) since Mon 2016-07-11 13:16:18 BRT; 28min ago
Process: 1046 ExecStart=/etc/rc.d/rc.local start (code=exited, status=0/SUCCESS)
CGroup: /system.slice/rc-local.service
├─2272 /bin/sh /oracle/domains/mywl_domain/startWebLogic.sh
├─2284 /bin/sh /oracle/domains/mywl_domain/bin/startWebLogic.sh
├─2374 /bin/sh /oracle/domains/mywl_domain/bin/startNodeManager.sh
├─2377 /bin/sh /oracle/binaries/wlserver/server/bin/startNodeManager.sh
├─2428 /oracle/jdk1.7.0_25/bin/java -Dwls.home=/oracle/binaries/wlserver/server -Dweblogic.home=/oracle/binaries/wlserver/server -server -Xms1g -Xmx1g -XX:MaxPermSize=512m -Dcoherence...
└─2442 /oracle/jdk1.7.0_25/bin/java -server -Xms1g -Xmx1g -XX:MaxPermSize=512m -Dweblogic.Name=AdminServer -Djava.security.policy=/oracle/binaries/wlserver/server/lib/weblogic.policy .

Maiquel.
 

Weblogic starting with the operating system

Hi,
Today, let’s to configure weblogic services startup, when machines starts.
In some blogs, we can find a bunch of customized scripts that create and set variables to startup the adminservers, nodemanagers and managed server, but, in my case, i just need to start adminserver and nodemanger, when machines start just after an incident.

For this situation, we need that the startup of application do not interrupt the operation system startup.

*The operation system in subject is Red-Hat 6.5

More“Weblogic starting with the operating system”

Changing ACFS mount point

I do checked there’s no good way to change ACFS mounting point on asmca assistant, so I decided to document how I quickly change ACFS mount point:

    1. MAKE BACKUP ( in my case, there are no data loss );
    2. Do bellow:
root@mymachine:/oracle/product >/grid/product/12.1.0.2/bin/srvctl stop filesystem -d /dev/asm/ggatebin-68

root@mymachine:/ >/usr/sbin/acfsutil registry -d /dev/asm/ggatebin-68
acfsutil registry: successfully removed ACFS volume /dev/asm/ggatebin-68 from Oracle Registry

root@mymachine:/ >/usr/sbin/acfsutil registry -a /dev/asm/ggatebin-68 /oracle/product/goldengate12c/
acfsutil registry: mount point /oracle/product/goldengate12c successfully added to Oracle Registry

root@mymachine:/oracle/product >chown -R oracle.oinstall goldengate12c
root@mymachine:/oracle/product >chmod 755 goldengate12c

Maiquel.

kernel.panic_on_oops: New Oracle 12c Installation Requirement

Hi all,
Do you know what mean the parameters on installing 12c?

This parameter controls the kernel’s behaviour when an oops or bug is encountered:

  • 0: try to continue operation
  • 1: panic immediately.  If the `panic’ sysctl is also non-zero then the machine will be rebooted.

OOPS is a deviation from correct behavior of the Linux kernel, one that produces a certain error log.
The better-known kernel panic condition results from many kinds of oops, but other instances of an oops event may allow continued operation with compromised reliability.

This is recommended in a system where we want to have node evicted in case of any hardware failure or any other issue.

To adjust as recommended by Oracle?
1. Put an entry in sysctl.conf for having it permanent:

kernel.panic_on_oops = 1

2. Refresh running command:

sysctl -p

KB: https://www.kernel.org/doc/Documentation/sysctl/kernel.txt

Matheus.

Installing and Configuring ASMLIb on Oracle Linux 7

Hi all!
For those are familiar with RHEL/OEL 4 and 5, there is some differences to start ASMLib on OEL 6 and 7.

spanner.png
So, a quick guide to install (done on OEL 7), start and configure:

1. Install the ASMLib kernel module package as root using the following command:

yum install kmod-oracleasm

2. Install the ASMLib library package and utilities package

yum install oracleasm-support oracleasmlib oracleasm-`uname -r`

It’s possible some package to not found. For example:

No package oracleasmlib available.

So, you can download rpm libs from here and install via rpm:

[root@dbsrv01 oracle]# rpm -Uvh ~/oracleasmlib-2.0.12-1.el6.x86_64.rpm
Preparing...                          ################################# [100%]
Updating / installing...
1:oracleasmlib-2.0.12-1.el6        ################################# [100%]

Ok, now, lets configure/start services:

[root@dbsrv01 ~]# /etc/init.d/oracleasm configure

Nothing happen? Ok, let’s try to start it:

[root@dbsrv01 ~]# /etc/init.d/oracleasm start
Starting oracleasm (via systemctl):  Job for oracleasm.service failed because the control process exited with error code. See "systemctl status oracleasm.service" and "journalctl -xe" for details.
[FAILED]

Hmmm… Are these commands correct?

[root@dbsrv01 ~]# /etc/init.d/oracleasm
Usage: /etc/init.d/oracleasm {configure|createdisk|deletedisk|querydisk|listdisks|scandisks|status}

Ok… So, what to do?

Take a look:

[root@dbsrv01 ~]# oracleasm init
Creating /dev/oracleasm mount point: /dev/oracleasm
Loading module "oracleasm": oracleasm
Configuring "oracleasm" to use device physical block size
Mounting ASMlib driver filesystem: /dev/oracleasm

Victory!
Now, let’s configure:

[root@dbsrv01 ~]# oracleasm configure
ORACLEASM_UID=
ORACLEASM_GID=
ORACLEASM_SCANBOOT=true
ORACLEASM_SCANORDER=""
ORACLEASM_SCANEXCLUDE=""
ORACLEASM_USE_LOGICAL_BLOCK_SIZE="false"

It shows, but how configure?

Just put “-i” clause, like:

[root@dbsrv01 ~]# oracleasm configure -i
Configuring the Oracle ASM library driver.
This will configure the on-boot properties of the Oracle ASM library
driver.  The following questions will determine whether the driver is
loaded on boot and what permissions it will have.  The current values
will be shown in brackets ('[]').  Hitting  without typing an
answer will keep that current value.  Ctrl-C will abort.
Default user to own the driver interface []: grid
Default group to own the driver interface []: oinstall
Scan for Oracle ASM disks on boot (y/n) [y]: y
Writing Oracle ASM library driver configuration: done

And you can list again:

[root@dbsrv01 ~]# oracleasm configure
ORACLEASM_UID=grid
ORACLEASM_GID=oinstall
ORACLEASM_SCANBOOT=true
ORACLEASM_SCANORDER=""
ORACLEASM_SCANEXCLUDE=""
ORACLEASM_USE_LOGICAL_BLOCK_SIZE="false"
[root@dbsrv01 ~]# oracleasm status
Checking if ASM is loaded: yes
Checking if /dev/oracleasm is mounted: yes

To add a disk, the same process can be followed on earlier versions:

[root@dbsrv01 ~]# oracleasm createdisk SDD /dev/sdd1
Writing disk header: done
Instantiating disk: done
[root@dbsrv01 ~]# oracleasm listdisks
SDD

For all commands:

[root@dbsrv01 ~]# oracleasm -h
Usage: oracleasm [--exec-path=]  [  ]
oracleasm --exec-path
oracleasm -h
oracleasm -V
The basic oracleasm commands are:
configure        Configure the Oracle Linux ASMLib driver
init             Load and initialize the ASMLib driver
exit             Stop the ASMLib driver
scandisks        Scan the system for Oracle ASMLib disks
status           Display the status of the Oracle ASMLib driver
listdisks        List known Oracle ASMLib disks
querydisk        Determine if a disk belongs to Oracle ASMlib
createdisk       Allocate a device for Oracle ASMLib use
deletedisk       Return a device to the operating system
renamedisk       Change the label of an Oracle ASMlib disk
update-driver    Download the latest ASMLib driver

And to see arguments for each one:

[root@dbsrv01 ~]# oracleasm configure -h
Usage: oracleasm-configure [-l ] [-i|-I] [-e|-d] [-u ] [-g ] [-b|-p] [-s y|n] [[-o ] ...] [[-x ] ...]

Have a nice day!
See ya!
Matheus.

nc -l – Starting up a fake service

Hi everyone!

Recently i have faced a situation that made me find out a very nice and useful command that helped me a lot, and i hope it comes to help you guys as well, and it’s named:

nc

Situation: We have a replicated environment from one datacenter to another (Using Golden Gate), where the ETL happens. So basically is:

Datacenter 1 (root data)

Replicates to datacenter 2 (transforming the data)

that replicates to datacenter 3 (production itself)

In Datacenter level 2, we have a dataguard configured. So then came the question:

  • What if we need to do the switchover to the standby environments?
  • Will we gonna have everything we need properly set up for the replication?
  • How are we going to test the ports if nothing is up in there? Aren’t we gonna get “connection refused”?

Calm down! There is a very nice workaround for this.

All you need to do is install the nc command as root (if it is not installed already):

yum install nc

Then execute it as follows, on the server you wanna test:

nc -l

example:

I wanna make sure that on the standby server the port 7809 (Golden Gate MANAGER port) is open. On the standby server you run:

nc -l 7809

Then, from a remote server, you are going to be able to connect through a simple telnet command:

telnet server.domain port

example:

telnet standby.company.com 7809

 

ON PRACTICE:

  • Try the telnet from the remote server to the standby:

remoteserver {/home/oracle}: telnet standby.server 7809

Trying 192.168.0.10…

telnet: connect to address 192.168.0.10: Connection refused

  • Then we start the fake service on the standby server!

standby.server {/home/oracle}: nc -l 7809

  • And try the telnet again:

remoteserver {/home/oracle}: telnet standby.server 7809

Trying 192.168.0.10…

Connected to standby.server.

Escape character is ‘^]’.

 

Cheers!

Rafael.

AIX: NTP Service Basics

Hi all,
I always forget the command and have to search it again. For further searches, I expect to found in my own posts… 🙂

> To start Service

startsrc -s xntpd

> To stop Service

stopsrc -s xntpd

> Configuration File

/etc/ntpd.conf

Expect it be useful to you too.
See ya!
Matheus.

Linux: Resizing Swap Online

Hi all!
Quick one to resize swap online:

[root@server-db ~]# swapon -s
Filename                                Type            Size    Used    Priority
/dev/mapper/rootvg-lvswap              partition       5242872 373624  -1
[root@server-db ~]# vgs
VG                #PV #LV #SN Attr   VSize   VFree
[...]
rootvg              1   6   0 wz--n- 135.69G 5.69G
[...]
[root@server-db ~]# lvextend -L +2048M /dev/mapper/rootvg-lvswap
Extending logical volume lvswap to 7.00 GB
Logical volume lvswap successfully resized
[root@server-db ~]# vgs
VG                #PV #LV #SN Attr   VSize   VFree
[...]
rootvg              1   6   0 wz--n- 135.69G 3.69G
[...]
[root@server-db ~]# mkswap /dev/mapper/rootvg-lvswap
Setting up swapspace version 1, size = 7516188 kB
[root@server-db ~]# swapoff /dev/mapper/rootvg-lvswap
[root@server-db ~]# swapon /dev/mapper/rootvg-lvswap
[root@server-db ~]# swapon -s
Filename                                Type            Size    Used    Priority
/dev/mapper/rootvg-lvswap              partition       7516188 373624  -1

See ya!
Matheus.

Linux Basic: Creating a Filesystem

From disk to filesystem:

> Rescan on scisi controller to detect the disk (controller id 0, in  this example)

echo "- - -" > /sys/class/scsi_host/host0/scan

– List disks

fdisk -l

> Fdisk choosing options n -> new p->partition 1-> partition number

fdisk /dev/sdm

> Create physcal volume

pvcreate /dev/sdm1

> Create Volume Group

vgcreate oracle /dev/sdb1

> Rename Volume Group

vgrename oracle vgoracle

> Create LV

lvcreate -L 19G -n lvoracle vgoracle

> Extend LV

lvextend -L +990M /dev/vgoracle/lvoracle

> Make FileSystem

mkfs.ext3 -m 0 -v /dev/vgoracle/lvoracle

OBS: m 0 is the journal (for recovery in case of crash).  “0” because I don’t want it now. So, 100% of disco will be available for using on fs.

> Mount filesystem on Directory

mount -t ext3 /dev/vgoracle/lvoracle /oracle/

> Just to check:

$ df -h
/dev/mapper/vgoracle-lvoracle
20G  173M   20G   1% /oracle

 

Have a nice day!
Matheus.