hostname in Oracle Linux 7.x ändern

~ spa ~ Kommentar hinterlassen

Möchte man in Oracle Linux Version 7.x (ich nutze hier im Beispiel OL 7.5) den „hostname“  ändern, hat man drei Möglichkeiten:

NetworkManager text user interface tool


# nmtui

Menüpunkt auswählen Namen setzen abspeichern fertig

NetworkManager command line tool „nmcli“ 

 


# nmcli general hostname

Setzen des hotsname mit

# nmcli general hostname o2

 

Das „hostnamectl“ Kommando


# hostnamectl set-hostname o2 --static

Überprüfen kann man seine „Arbeit“ wie folgt


# hostnamectl status
Static hostname: o2
Icon name: computer-vm
Chassis: vm
Machine ID: 5c05aeb9cab3438dbc844003961fbd80
Boot ID: 22defd0162b74819b8680e1857182c4b
Virtualization: kvm
Operating System: Oracle Linux Server 7.5
CPE OS Name: cpe:/o:oracle:linux:7:5:server
Kernel: Linux 4.1.12-124.16.4.el7uek.x86_64
Architecture: x86-64

Die einfachste und schnellste Variante ist tatsächlich „nmtui“

Advertisements

Oracle DB Upgrade 12.1 auf 12.2

~ spa ~ Kommentar hinterlassen

Ich bin gerade dabei einige Datenbanken von 12.1 -> 12.2 upzugraden. Dazu setzte ich den DBUA ein und bin sehr positiv überrascht. Viele Checks werden im Dialog abfragt und diese werden dann während des Upgrade Prozess umgesetzt. Der Upgrade läuft reibungslos durch auch wie in meinem Fall auf RAC Datenbanken.

Möchte man den Pre-Upgrade vorab durchführen und dies per Skript steuern, dann kann man auf Metalink dazu ein Skript herunterladen. Dieses Skript sammelt die relevanten Daten, welche man dann vorab analysieren kann.

Doc ID 556610.1 – Script to Collect DB Upgrade/Migrate Diagnostic Information (dbupgdiag.sql)

Die komplette Checklist für den Upgrade per DBUA wird dann in der folgenden Doc ID beschrieben.

Doc ID 2189854.1 – Complete Checklist for Upgrading to Oracle Database 12c Release 2 (12.2) using DBUA

Im Nachgang muss dann noch der DB Parameter „compatible“ gesetzt werden.

Hierbei muss berücksichtigt werden, dass es kein Zurück mehr gibt. Ein Downgrade ist dann nicht mehr möglich.

alter system set compatible=’12.2.0.1′ …

Der DBUA in der Version 12.2 ist aus meiner Sicht sehr gut implementiert worden und hat viele wichtige Checks und Features an Bord.

Viel Spaß bei den nächsten Upgrades :-)

 

 

 

 

 

 

exachk 18.2.0_20180518 released

~ spa ~ Kommentar hinterlassen

Oracle released the new Version of exachk. The version is shown as 18.2.0_2018052018 so far so good. The next sentence in the Note is: „What’s new in exachk 12.2.0.1.4 may be found in the „What’s New in 12.2.0.1.4″ section of the User’s Guide available here..“

The new Release model from Oracle is really confusing. From my point of view it makes no sense that you download a Version as 18.2.0 and then the Documentation has a Version 12.2.0.1.4.

 

 

 

 

 

Exadata troubleshooting easy with GetExaWatcherResults.sh

~ spa ~ Kommentar hinterlassen

If you have for example a performance problem or a crash on your Exadata Machine and you need an overview about the machine then use the very powerful tool „GetExaWatcherResults.sh“ which based on the data of Exawatcher.

GetExaWatcherResults.sh give you a details about:

  • CPU utilization and details
  • IO Summary
  • and more

GetExaWatcherResults.sh will generate very good graphics and that is what I will show now.

How is the way to get these graphs?


Login as "root"

cd /opt/oracle.ExaWatcher

GetExaWatcherResults.sh --from 02/23/2018_08:00:00 --to 02/23/2018_13:00:00 --resultdir /tmp/exawatcher_230218

Next step



cd /tmp/exawatcher_230218

bunzip2 the archive and un tar it

tar xvf ExaWatcher_exa31_2018-02-23_08_00_00_5h00m00s.tar

 

Change to the newly created directory and you find the following files


index.html
exa31.net_cpu.html
exa31.net.html
exa31.net_iodetail.html
exa31.net_iosummary.html
exa31.net_menu.html
exa31.net_mp.html

 

Start a Browser on the Server or copy the files to your notebook and start analyzing


open the "index.html" files

here the details

 

 

It is easy to answer questions like

  • What is the CPU usage on Friday between 09:00 an 14:00 o’clock?
  • Where do we have a CPU peek during the business hours?

No problem with „GetExaWatcherResults.sh“ and if needed go deeper with other tools for example „awr – report“ on the database itself or an „ash-report“

Try it. It’s very helpful :-)

 

 

 

 

Secure Erase of an Exadata System

~ spa ~ 1 Kommentar

What has to be done when the Lifecycle of an Exadata System comes to the end.

You need to do an secure erase of DB and Storage nodes.

By the way you can also secure erase the Switches and PDU, etc. but this is not described in this article.

Documentation

https://docs.oracle.com/cd/E80920_01/DBMSQ/exadata-secure-erase.htm#DBMSQ-GUID-DE6BBDF7-6BCB-412B-AD1E-E0FFEEFCC3AA

and  My Oracle Support Doc ID 2180963.1

Steps to do

I use the method via bootable USB Stick

Download Boot Image via Patch 25470974

You need a complete list of all DB and Storage node names including all IP addresses of each ILOM Server

Tip: Before you start reset the password on each Server for example „welcome1“

Prepare USB Stick

I use my Mac book and do a „dd“ to copy the image to the USB Stick

dd if=image_diagnostics_12.2.1.1.0_LINUX.X64_170126.2-1.x86_64.usb of=/dev/disk2

Start a ILOM Web Console Login for the first Server

In parallel start a ILOM terminal console session to do a restart of the first Server

While the reset is running the Web  Console came up with the BIOS Splash screen. Please  enter


<CTRL+P>

It takes a while and you see the boot menu

Select the USB Stick and press enter to start

the Boot Screen appears

Now it is time to check the output on the ILOM terminal console. You will see after a while a „login:“ prompt


Login as "root" password "sos1exadata" or "sos1Exadata"

If the password doesn’t work contact Oracle Support for help

Weiterlesen „Secure Erase of an Exadata System“ →

Oracle Essential Support Tools im Exadata Umfeld

~ spa ~ Kommentar hinterlassen

Mein DOAG Vortrag zum Thema

„Oracle Support wie gehe ich vor und welche Tools setze ich im Exadata Umfeld ein“

Exadata_Oracle_Support_V1.1

Hinweis:

In der Zwischenzeit hat Oracle eine neue Version den Trace File Analyzer bereitgestellt die man dann auch einsetzen sollte. Einfach über die Doc-ID suchen.

TFA Collector – TFA with Database Support Tools Bundle (Doc ID 1513912.1)

Noch eine Anmerkung für alle die gerade PSU’s etc. eingespielt haben. Leider stellt Oracle Support nicht die oben genannte TFA Version 12.2.1.3.0 mit dem letzten PSU zur Verfügung.  Die Installation des Trace File Analyzer muss separat durchgeführt werden.

 

 

Exadata Flash Cache enabled for Write Back

~ spa ~ Kommentar hinterlassen

During Tests for an Migration of a major customer application we saw in our AWR reports that most of the jobs are very write intensive. This was the point where we would like to test what happens when we change the Flash Cache Mode from Write Through to Write Back.

What are the main benefits of Write Back mode:

  • it improves the write intensive operations while writing to flash cache is faster than writing to normal Hard disks
  • on Exadata X3  and newer machines write performance can be improved up to 20X IOPS
  • The Write Back Flash Cache accelerates reads and writes for all workloads

First of all I take a look in Metalink and found a Doc ID 1500257.1 with more details.

What are the requirements?

since April 2017 it is default if the following conditions are full filled:

  • Grid and RDBMS Home
    • 11.2.0.4.1 or higher
    • 12.1.0.2 or higher
    • 12.2.0.2 or higher

and

  • DATA diskgroup has HIGH redundancy

When should I use Write Back?

  • It makes sense if your application is write intensive
  • You find significant waits for „free buffer waits“
  • High IO times to check for write bottlenecks in AWR reports

What are the steps to enable Write Back?

We have the possibility to do it „offline“ so we stop the whole Grid & Rdbms Stack, but you can change it also in a Rolling manner.

  • Actual Flash Cache Mode

dcli -g cell_group -l root "cellcli -e list cell attributes flashcachemode"
cel04: WriteThrough
cel05: WriteThrough
cel06: WriteThrough
cel07: WriteThrough
  • Stop the whole Cluster

crsctl stop cluster -all -f
  • Check State of Flash Cache

name: cel04_FLASHCACHE
status: normal

name: cel05_FLASHCACHE
status: normal

name: cel06_FLASHCACHE
status: normal

name: cel07_FLASHCACHE
status: normal
  • Steps for the Change

These steps has to be done on every Cell Server here as an example

Drop the flash cache on that cell

CellCLI> drop flashcache;
Flash cache cel04_FLASHCACHE successfully dropped.

Shut down Cell service

CellCLI> alter cell shutdown services cellsrv;
Stopping CELLSRV services... The SHUTDOWN of CELLSRV services was successful.

Change Cell Flash Cache mode to Write Back

CellCLI> alter cell flashCacheMode=writeback;
Cell cel04 successfully altered 

Restart the Cell Service

CellCLI> alter cell startup services cellsrv;
Starting CELLSRV services...
The STARTUP of CELLSRV services was successful.

Recreate the Flash Cache

CellCLI> create flashcache all;
Flash cache cel04_FLASHCACHE successfully created

Finally check the State on all Cell Server dcli -g cell_group -l root "cellcli -e list cell attributes flashcachemode"
cel04: WriteBack
cel05: WriteBack
cel06: WriteBack
cel07: WriteBack

So the first step was done and now the tests can go on.

In a few weeks I will give a feedback what are the real improvements so stay tuned.

 

 

 

 

Important Change for Grid 12.2 Upgrade and MGMTDB

~ spa ~ 1 Kommentar

I just did an Grid Infrastructure Update to Oracle 12.2 with the latest PSU Aug 2017.

I did my preparation with the help of the Doc ID 2111010.1

„12.2 Grid Infrastructure and Database Upgrade steps for Exadata Database Machine running 11.2.0.3 and later on Oracle Linux“

In the Post-upgrade Steps was written that the Management DB should be deconfigured

  • Post-upgrade Steps

      • Deconfigure MGMTDB

 

The deconfigure is obsolete and the MGMTDB is now part of the Update. 

Here the original text from the Doc ID.

September 28,2017
  • MGMTDB will now be part of upgrade, the flags to reove and deconfigure are removed.

 

 

For me it looks like that the revision of the document is not yet finished

So if you plan a Grid Upgrade in the near future read the document very carefully and if needed open an SR