RHEL: Figuring out CPUs, Cores and Hyper-Threading

Hi all!
It’s a recurrent subject, right? But no one is 100% sure to how figure this out… So, let me quickly show you my way:

– Physical CPUs (sockets):

[root@mysrvr ~]# grep -i "physical id" /proc/cpuinfo | sort -u | wc -l
2
[root@mysrvr ~]# dmidecode -t processor |grep CPU
        Version: Intel(R) Xeon(R) CPU X5570 @ 2.93GHz
        Version: Intel(R) Xeon(R) CPU X5570 @ 2.93GHz

So, 2 physical CPUs.

– Physical Cores

[root@mysrvr ~]# egrep -e "core id" -e ^physical /proc/cpuinfo|xargs -l2 echo|sort -u
physical id : 0 core id : 0
physical id : 0 core id : 1
physical id : 0 core id : 2
physical id : 0 core id : 3
physical id : 1 core id : 0
physical id : 1 core id : 1
physical id : 1 core id : 2
physical id : 1 core id : 3

Each one of Physical Processors has 4 cores.
So, there is two quad-cores. This way, we have 8 cores at all.

– Logical CPUs

[root@mysrvr ~]# grep -i "processor" /proc/cpuinfo | sort -u | wc -l
16

Ok, so we have cores in double.
This means we have Hyper-Threading (technology by Intel Processors).

Not so hard, right?

Those links are similar and quite cool to understand the concepts:
https://access.redhat.com/discussions/480953
https://www.redhat.com/archives/redhat-list/2011-August/msg00009.html
http://www.intel.com/content/www/us/en/architecture-and-technology/hyper-threading/hyper-threading-technology.html

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.

OUI: RHEL Permission Denied error

Another quick tip about running DBCA:

# Error:

[oracle@dbsrv database]$ ./runInstaller
Starting Oracle Universal Installer...
Checking installer requirements...
All installer requirements met.
Preparing to launch Oracle Universal Installer from /tmp/OraInstall2015-06-25_06-37-23PM. Please wait ...Error in CreateOUIProcess(): 13
: Permission denied

# Solution:

mount -t ext3 -o remount default /tmp

Ok doke?

Matheus.

RHEL5: Database 10g Installation – Checking operating system version error

Everything is old. RHEL and Database versions. But can be useful if you are preparing a nonprod lab of your legacy env, right?

Let’s see the problem:

[oracle@dbsrv database]$ ./runInstaller
Starting Oracle Universal Installer...
Checking installer requirements...
Checking operating system version: must be redhat-3, SuSE-9, redhat-4, UnitedLinux-1.0, asianux-1 or asianux-2
Failed <<<<

The “easiest” workaround:

[oracle@dbsrv database]$ ./runInstaller -ignoreSysPrereqs

The “hardway” workaround:

1. Copy parameter file:
$ cp database/install/oraparam.ini /tmp
2. Edit parameter file:
$ vi /tmp/oraparam.ini
2.1. Change
[Certified Versions]
Linux=redhat-3,SuSE-9,redhat-4,UnitedLinux-1.0,asianux-1,asianux-2
to
[Certified Versions]
Linux=redhat-3,SuSE-9,redhat-4,UnitedLinux-1.0,asianux-1,asianux-2,redhat-5
3. Run the installer again:
$ ./runInstaller -paramFile /tmp/oraparam.ini

KB: Requirements For Installing Oracle10gR2 On RHEL 5/OEL 5 (x86_64) [ID 421308.1]

Matheus.

ORA-00845: MEMORY_TARGET not supported on this system (RHEL)

# Solution:
Make sure that /dev/shm is mounted. You can check this by typing df -k at the command prompt. It will look something like this:

Filesystem Size Used Avail Use% Mounted on

shmfs 1G 512M 512M 50% /dev/shm

If you don’t find it then you will have to manually mount it as root user. The size should be more than MEMORY_TARGET or MEMORY_MAX_TARGET.

For example, if the MEMORY_TARGET is less than 2 GB, you should make like that:

#root: mount -t tmpfs shmfs -o size=2048m /dev/shm

I recommend you add an entry in /etc/fstab so that the mount remains persistent even after a reboot.
To make it, add the following entry in /etc/fstab:

shmfs /dev/shm tmpfs size=2048m 0 0

Helped?
Share this post!

Matheus.

Error: Starting ACFS in RHEL 6 (Can’t exec “/usr/bin/lsb_release”)

Quick tip:

# Error:
[root@db1gridserver1 bin]# ./acfsload start -s
Can’t exec “/usr/bin/lsb_release”: No such file or directory at /grid/product/11.2.0/lib/osds_acfslib.pm line 511.
Use of uninitialized value $LSB_RELEASE in split at /grid/product/11.2.0/lib/osds_acfslib.pm line 516.

# Solution:
[root@db1gridserver1 bin]# yum install redhat-lsb-core-4.0

Note: Bug 17359415 – Linux: Configuring ACFS reports that cannot execute ‘/usr/bin/lsb_release’ (Doc ID 17359415.8)

Matheus.