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How To Erase Data Securely On Exadata?

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Give more attention who are looking to attend 1Z0-027 exam, you can expect 1-2 questions from this topic.

When disposing of an old hard drive, physically destroy the drive or completely erase all the data on the drive. Deleting the files or reformatting the drive removes only the address tables on the drive. 


The information can still be recovered from a drive after deleting files or reformatting the drive.

To overcome from this we can securely erase and clean physical disk before redeployment of it using Oracle Exadata Storage Server Software. There are multiple options to overwrites existing contents on the disks like one pass, three passes or seven passes. 

1pass option overwrites contents with zeros. This option is not applicable for flash drives. 

3pass option overwrites with set data patterns. It follows the recommendations from NNSA (United States National Nuclear Security Administration ). This option is also not applicable for flash drives.

7pass option also overwrites with set data patterns. It follows the recommendations from DOD.

Below tables shows approximate time needed to securely erase data using above options.



How we can use this option while erasing data?

The CellCLI DROP CELLDISK command includes an option to securely erase data by overwriting the data. If Exadata Storage Server drives contain sensitive data that needs to be erased for redeployment or another purpose, then the secure erase feature should be used on the storage cell. 

The ERASE option ensures that all data is overwritten with random data, and erased up to seven times. This ensures that the data cannot be recovered, and that the data is permanently erased.

Erase data using Drop CELLDISK

Syntax:

DROP CELLDISK { ALL [FLASHDISK | HARDDISK] | cdisk_name [,disk_name]... } [ERASE = value [NOWAIT]] [FORCE] 

Purpose:
  • This command is necessary if a cell disk fails, or it is replaced by a newer model. 
  • Before dropping the cell disk, you should drop its grid disks and the corresponding Oracle ASM disks from the disk groups. 
  • The Oracle ASM disks should be dropped before dropping the grid disks.

Usage:
  • If the ALL option is specified, then all the cell disks on the cell are removed
  • If individual cell disks are specified, then the named cell disks (cdisk_name) are dropped.
  • When dropping all cell disks using the 1pass or 3pass option, it necessary to drop the flash disks first using the 7pass option, and then drop the cell disks
  • Use the NOWAIT option with the ERASE option to run the command asynchronously
  • If the LUN associated with the CELLDISK is flagged as automatically created, then that LUN is deleted along with the cell disk.

Example:

CellCLI> DROP CELLDISK CD_03_cell01
CellCLI> DROP CELLDISK CD_02_cell06 FORCE
CellCLI> DROP CELLDISK ALL
CellCLI> DROP CELLDISK CD_02_cell09 ERASE=1pass NOWAIT
CellDisk CD_02_cell09 erase is in progress 

Erase data using Drop Griddisk

Purpose:


The DROP GRIDDISK command removes the named grid disks from the cell or removes all the grid disks specified by the ALL PREFIX option.

Syntax:

DROP GRIDDISK {ALL [FLASHDISK | HARDDISK ] PREFIX=gdisk_name_prefix , | gdisk_name [, gdisk_name]... } [ERASE = value [NOWAIT]] [FORCE]

Usage:
  • If the gdisk_name is entered, then the name identifies the individual grid disk to be removed. Multiple names can be entered.
  • The FLASHDISK option limits the DROP GRIDDISK command to grid disks that are flash disks.
  • The HARDDISK option limits the DROP GRIDDISK command to grid disks that are hard disks.
  • The ERASE option erases the content on the disk by overwriting the content
  • Use the NOWAIT option with the ERASE option to run the command asynchronously
  • When dropping all grid disks using the 1pass or 3pass option, it necessary to drop the flash disks first using the 7pass option.

Example:

CellCLI> ALTER GRIDDISK data01_CD_03_cell01 INACTIVE
CellCLI> DROP GRIDDISK data01_CD_03_cell01
CellCLI> DROP GRIDDISK ALL PREFIX=data01
CellCLI> DROP GRIDDISK data02_CD_04_cell01 FORCE
CellCLI> DROP GRIDDISK data02_CD_04_cell01 ERASE=1pass
GridDisk data02_CD_04_cell01 successfully dropped
CellCLI> DROP GRIDDISK ALL FLASHDISK PREFIX=DATA, ERASE=7pass
CellCLI> DROP GRIDDISK ALL PREFIX=DATA, ERASE=3pass 

Check the status of secure Erase:

CellCLI> LIST GRIDDISK
DATA_CD_03_cell1 erase in progress
DATA_CD_04_cell1 erase in progress
DATA_CD_06_cell1 active
DATA_CD_05_cell1 active

You can go through the Oracle Exadata Documentation for more information.

You would also like :


Why You Should Be Oracle Exadata Certified?

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When you hear word Exadata , what first thing comes in your mind? Now the time comes for Exadata DMArather than traditional DBA who can manage entire setup including network, storage, server, operating system, database, grid, asm etc...

To get this job you have to demonstrate your skill to the customer which is definitely 50% fulfilled if you are exadata certifiedIf you go to any Oracle customer who are on traditional oracle setup, all are thinking switch to the exadata machine because of many benefits for business as well operational.

The level of demand continues to grow with each new version of exadata around the world. Lots of Oracle professionals are there but if you are certified with exadata than it will raise your visibility and increase the chance to get a job with high salary. It will also help you to be ahead than others who are still working as traditional DBAs.

We are not saying that there is no scope for traditional DBAs but certainly better scope who has exadata certification credentials and knowledge. No doubt certification is not an indicator of a person's ability to do a job but definitely it will make a different impression on the employer if you are certified. Now a days customer also ask whether employee are certified or not, based on that they decide to do the business with any firm so in this case certification will help to grab the opportunity.


"If two people with roughly the same background and experience are vying for the same job, the certified person will usually get to the top of the HR pre-screening pile. Certification gives an employee the edge."
           - Hans Forbrich, CEO, Forbrich Computing, provider of Oracle Certification

As a fresher you don't have that much knowledge but if you are certified than you can get better chance than others as it will at least show a certain level of knowledge and a commitment to learning the Oracle technology. If you see around, demand is growing for Oracle exadata professional. In near future it could be possible that small or big organization has to move on exadata either on private or public cloud.

Certification credentials also helps you to improve your earning power. Companies value skilled workers. According to Oracle's 2012 salary survey, more than 80% of certified individuals reported a promotion, compensation increase or other career improvements as a result of becoming certified.

This is the right time to earn exadata certification credentials because of the limited resource availability in the market, you can grab the opportunity to make your place as a DMA.

If you want to easily obtain your exadata certification, the first thing that you should consider is to demonstrate your abilities and excellent knowledge. Those individuals and consultants who already attain their professional level exadata Certification belongs to elite group and at the same time they have exceptional and successful career than those individuals and consultant who have not yet obtain their exadata Certification. 

Exadata certification is also considered as long term investment that will greatly help you to attain your future career success. The success in obtaining exadata certification cannot be done overnight since it requires time, effort, passion, dedication and hard work.

It is very important to know the types of exadata certification. Choose wisely which can fit in your role. You can also go for both which will make your profile brighter.

Remember only passing this exam will not help you. You have to clear the interview which obviously more over on database machine. You can go through the post where we have covered generic Exadata Interview Questions and Answers.

There are two type of certifications available one is for implementer and other one is for administrator.

1. Oracle Exadata Database Machine 2014 Implementation Essentials (1Z0-485)

It covers exadata architecture,features, configuration, maintenance, support. This is more over covers exadata implementation part.

2. Oracle Exadata X3 and X4 Administration (1Z0-027)

This certification helps for the role of exadata Administrator. This is advance certification the 1Z0-485, it required in depth knowledge of exadata administration.

It covers exadata features and configurations, exadata Storage Server; migrating to the Database Machine; and maintaining, monitoring and optimizing the Database Machine after initial configuration. In short it covers whole administration tasks which are required to manage the exadata machine.


You can follow our Exadata Certification Question Bank to achieve maximum success in your Exadata certification.

How To Deinstall OEM12c agent and Remove Its Targets from OMS repository?

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Recently we have added target with wrong name hence it was required to deinstall OEM12c agent and associated targets from OMS repository.

Below steps would help you to perform this activity.


1. Deinstall agent from host/target

Export EM Agent HOme

$export EMAGENT_HOME=/u01/app/oracle/product/emagent/core/12.1.0.5.0

Deinstall Agent

$perl $EMAGENT_HOME/sysman/install/AgentDeinstall.pl -agentHome $EMAGENT_HOME

Note: 

Above step will only deinstall EM agent from host. It will not remove the targets from OMS repository. Make sure to delete the targets manually from the Cloud Control Console for a successful de-installation. To remove those targets you have to follow below steps. 

2. Once agent get deinstall, remove that target and associated monitored target from OMS repository

Login to emcli

$ cd $OMS_HOME/bin

$ ./emcli login -username=SYSMAN -password=

Delete target from OMS

$ ./emcli delete_target -name="db01.company.com:3872" -type="oracle_emd" -delete_monitored_targets

It should remove database host target and all associated targets from OMS repository.

Tips To Clear Oracle Exadata Certification Exam

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Many DMA positions are available when you look for Oracle Exadata jobs, but it requires some skills to meet the job requirement. Credential of Oracle exadata certification is most appropriate for these position which can give confidence to the employer that you have a necessary skill to land for a job.


Oracle Exadata Certification is considered to be a one way ticket to a mouth-watering career in the field of Oracle Exadata Administrator, consultant and Implementer.

Today there are huge demand for Oracle Exadata Specialist in various industries. Also you can say DMA job is recession proof job in Oracle Database Technology.

Oracle offers two types of Exadata certifications. 

If you are beginner and responsible more over for implementation than this is the right certification for you. This is also easier than administrator exam. If you are seriously want to make a career as DMA than first your should start with this certification. This one is bit easier so once you clear this exam, you will get more confidence for another one.


This exam is designed specially for exadata machine administrator. It required in depth study before appearing into the exam. It includes all the topics in detail which will help you in your day to day job.

Following are some suggestion which will help you to clear the certification.
  1. First decide which certification is fits for your profile
  2. You should not just aim to clear the certification but you should also have good interest toward the technology. Believe us this will help you to gain more confidence.
  3. Get the exam details like number of questions, exam duration
  4. Calculate how much time you will get for each question which will help you to manage the time for each question while appearing into the exam 
  5. Go through the list of topics which will be asked in the examination
  6. Download Oracle Exadata Documentation 
  7. Read the reviews who already appeared into the certification, which will help you to get your direction for preparation of exam
  8. Make a habit of note down important points while preparing for the exam which will help you in last moment preparation
  9. Practice exam using exam study materials and exam simulator. It will help you to know on which area your are weak and accordingly you can give the time to those topics.
  10. If you have any doubt than ask someone who has cleared or who knows the topics very well. You can also write down your query to us.
  11. Once you are ready with all your preparation, book a time slot for the exam
  12. Reach early to the exam center. At least before 30 min which will give you enough time for exam formality
  13. Before answering any question even if you know the answer,read question properly
  14. If you feel you have any doubt about your answer, mark as review so that you can review at the end
  15. If you don't know answer for any question don't waste more time on that. Just pick a random answer, mark as review and move on
  16. If you have sufficient time than go back to the the questions which you have marked for review. Even if you have not marked than also going back second time will give you additional points.
You can follow our Exadata Certification Question Bank to achieve maximum success in your Exadata certification exam.

Oracle Is Slow, Is There Anything Wrong With Database?

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Whenever there is any application slowness or any other performance issue, regardless of source of the problems, the first question comes to DBA that Oracle is slow, is there anything wrong with database?


As a DBA we use to face this situation day to day. This doesn't mean there is no problem from database but many times it could be a server, storage or network bottleneck. May be issue with application coding.

In order to provide quick solution DBA will do some troubleshooting on database level and try to find out if there is any bottleneck in database but if dba can not identify issue or others would not identify it till the time finger will be on database.

Traditional DBA will diagnose problem in database but an expert DBA will try to find the issue on database as well on server level. 

In such scenario DBA must be familiar with the operating system commands used to extract information from the server. Need to analyse CPU, Memory, Network and Storage performance.

To analyse this you need to know some basic server level utility which can give you brief details regarding server resources and help you to reach at the source of problem. If you are a DMA or planning to make a career in DMA than this is perfectly fits for your profile.

Following are some performance monitoring tool to analyse the server performance. 

vmstat (Virtual Memory Statisctis)

Monitors processes, CPU, memory, or disk I/O bottlenecks. It is used to quickly identified server bottleneck. It displays real time information about process, memory, paging, disk I/O and CPU usage. If you server seems sluggish, then vmstat output will help you to determine which resource are being consumed.


watch

This utility use to run command periodically.




ps (Process)

Use the ps command to identify the process IDs of sessions consuming the most CPU on the server. This next ps command displays the top ten CPU-consuming statements and the associated process IDs. Use to find out the session based on the most consuming system resource.


top

This utility is used  to quickly identify which processes are the highest consumers of resources on the server. by default top is repetitively refresh utility. While top is running we can change output interactively.


mpstat (Multiple Processor Statistics)

mpstat utility is use to to determine CPU statistics. It gives broad view for CPU consumption for each CPU.


sar (System Activity Reporter)

This utility is useful to display current and historical processor load.  You can also get the statistics for different day of a month.


free

Useful to displays free and used memory and swap.


df (Disk Free)

Useful to display free and used disk space.


du (Disk Usage)

It displays free and used space on particular folder or disk


iostat (Input Output Statistics)

The iostat command can help you determine whether disk I/O is potentially a source of performance problems. This periodic extended output allows you to view in real time which devices are experiencing spikes in read and write activity.


netstat (Network Statistics)

Netstat is useful to display network traffic. 



You can follow our Exadata Certification Question Bank to achieve maximum success in your Exadata certification exam.

A Tour Of The Server ILOM Web GUI

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Oracle exadata is a combination of servers and storage cell. Each of this has ILOM interface which is used for hardware management and maintenance activity.

What is ILOM?

An ILOM is a service processor (SP) that is embedded into all Oracle Sun Server–based products.Oracle ILOM’s dedicated hardware and software is pre-installed on a variety of Oracle Sun server platforms.

What it Does?

The aim of an ILOM is to provide support for a server in a manner such that access to the data center is not required for day-to-day support functions.

An ILOM also provides access to a variety of diagnostic features and has integration with Oracle’s Automatic Service Request (ASR) to provide call-home functionality to report hardware failures to Oracle for fast support.

The Oracle ILOM service processors provide a wide array of features, and its functional aspects improve with every release of the ILOM.

The Oracle ILOM service processor (SP) runs its own embedded operating system and has a dedicated Ethernet port, which together provide out-of-band management capability

What it allows to do?
  • Remotely control the power state of your server
  • System monitoring
  • Remote KVMS capabilities
  • Fault display
  • Integration with a variety of authentication systems, such as LDAP, SSL, Radius and Active Directory
  • Remote syslog setup
  • SNMP and SMTP-based alerting
  • Updating the firmware
  • Environmental reporting
  • View the graphical and non-graphical consoles for the host
  • Gather the hardware diagnostics
  • Monitoring host states remotely
  • Access to various part and serial numbers
  • Determine the hardware configuration of your system

Oracle ILOM automatically initializes as soon as power is applied to the server. It provides a full-featured, browser-based web interface and has an equivalent command-line interface (CLI).

While login to the ILOM it will re-directed to below landing page which contain system summary with the current status. The Summary screen shown below is rich in information and allows you to get a lot of information summarized quickly.


We can launch server remote control by clicking on the launch remote console.Remote console helps to get login directly into the server.

Following are some snaps from ILOM console which helps to manage the server using ILOM.






























You can follow our Exadata Certification Question Bank to achieve maximum success in your Exadata certification exam.

Top 17 Open Ended Oracle DBA Interview Questions

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A good DBA will be able to teach, and train, others. So how do you find such a person? The answer is easy: you talk with them.



Than, why not ask the most basic questions you can, right from the start? The answer may surprise you, but the conversation is likely to reveal the depth of their experience right from the start.


Here are some basic open ended questions we have listed down which will help you as an interviewee as well interviewer.
  1. What is the most challenging aspect of your job?
  2. Do you treat your test and production systems differently? If so, why?
  3. How do you troubleshoot problems in your current role?
  4. What DBA activities you do everyday?
  5. What is your typical day like?
  6. What other parts of your organization do you interact with and how?
  7. Do you consider yourself a development DBA or a production DBA and why?
  8. What database and overall architecture would you suggest for testing new middleware without impacting production?
  9. Explain one backup and recovery scenario which you have performed
  10. What you will do if someone complain that database is running slow?
  11. How do you assess my database’s health?
  12. How would you approach a performance problem with a three-tier application?
  13. How do you test your backup/recovery procedures?
  14. How would you support the upgrade process for multiple applications,with different application rollout cycles, in the same instance?
  15. What should consist of DW Team?
  16. Why we should hire you?
  17. Can you explain which is the most difficult scenario which you have faced in your career?

You can also refer Exadata Interview Questions and Answers eBook to get maximum success in interview.

How To Change GRUB Password On Exadata Database Server?

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Let's first understand what is GRUB?

GRUB is Grand Unified Boot loader. It is a boot loader package from the GNU Project. GRUB is the reference implementation of the Free Software Foundation's Multiboot Specification, which provides a user the choice to boot one of multiple operating systems installed on a computer or select a specific kernel configuration available on a particular operating system's partitions.

Users can dynamically configure the GRUB subsystem. GRUB loads its configuration at startup, allowing boot-time changes, such as selecting different kernels or initial RAM disks. To this end, GRUB provides a simple, bash-like, command line interface, which lets users write new boot sequences on the fly, in addition to the normal menu lists.

GRUB is highly portable. It supports multiple executable formats and is geometry-translation independent. It supports all commonly used Unix file systems, the Windows file systems FAT and NTFS, and logical block addressing (LBA). GRUB allows users to view the contents of files on any supported file system. (Ref. - wikipedia)

Procedure to change the password is not Exadata specific but it is also applicable for all the the hardware which are running with Unix operating system.

The following procedure describes how to change the GRUB account password on the database server:

1. Use the following command at the operating system prompt to change the GRUB password:

#grub-md5-crypt

The system prompts for a new password. The new password must be entered twice, and a string is displayed.



2. Copy that string to the copy buffer.

$1$cfuQg$EWDMTiWJuyXvOSAZiw2qy. - This string need to be copied

3. Locate the password line in the /boot/grub/grub.conf file. The line looks similar to the following:

#password --md5 hashed_string


4. Replace the existing hashed string with the one copied from the grub-md5-crypt command output.


5. Save the file.

You have changed the GRUB password.

Top 5 Critical Factors To Determine Database Recovery Objectives

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Recovery of the database is the critical part of the backup and recovery strategy. Any database backup strategy is mainly governed by recovery requirements.


Following are the top critical factor which plays very important role while planing the backup and recovery strategy for Oracle database backup.

1. Recovery Time Objective (RTO): It is the target time you set for recovery of the database after any disaster. How quickly you recover the database that defines in RTO.

RTO has a broader purpose because it sets the boundaries for your whole business continuity management.

2. Recovery Point Objective (RPO): A Recovery Point Objective (RPO) is the maximum time frame your organization is willing to lose data for, in the event of database outage.

It is determined by looking at the time between data backups and the amount of data that could be lost in between backups.

What do RTO and RPO have in common? They are both crucial for business impact analysis and for business continuity management. Without determining them properly, you would be just guessing – and guessing is the best way to ensure you never recover from a disaster.

3. Performance: Often, whenever a backup kicks in, system performance is degraded. Does your OLTP take a hit when the backup kicks in? Do you need to minimize the impact of the backup on the running application because you need the application to be available 24/7? then you have to tune the system properly to minimize the impact on ongoing activity while backup is going on.

4. Retention: What is the backup retention policy? How many backups need to be stored on disks before they can be transferred to tape, archive, or a different tier storage?

5. Backup window: the period of time that a system is available to perform a backup procedure. Backup procedures can have detrimental effects to system and network performance, sometimes requiring the primary use of the system to be suspended. These effects can be mitigated by selecting proper backup window.

Oracle 11.2.0.3 To 12.1.0.2 Grid and Database Upgrade On Exadata

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Recently one of our consultant has upgraded grid and oracle database on Oracle Exadata from 11.2.0.3 to 12.1.0.2. He has shared upgrade instructions as per the Oracle best practice and documentation. 

Hope it will help who are planning to upgrade exadata environment.

If proper plan is in place than upgrade activity is not much difficult.

There are five main section for upgrade.

1. Prepare the Existing Environment
2. Install and Upgrade Grid Infrastructure to 12.1.0.2
3. Install Database 12.1.0.2 Software
4. Upgrade Database to 12.1.0.2
5. Post-upgrade steps



Now let's see what all are the steps need to perform for each section.

1. Prepare the Existing Environment

Steps need to be performed in this sections are:
  • Planning 
  • Review Database 12.1.0.2 Upgrade Prerequisites
  • Download and distribution of the required Files
  • Application of required patches
  • Run Exachk
  • Validate Readiness for Oracle Clusterware upgrade
  • Execute and verify output of cluster verification utility and act if anything need to be done

2. Install and Upgrade Grid Infrastructure to 12.1.0.2

This will perform grid installation and upgrade it to 12.1.0.2. The Grid Infrastructure upgrade is performed in a RAC rolling fashion, this procedure does not require downtime.

Data Guard

If there is a standby database, then run these commands on the standby system separately to upgrade the standby system Grid Infrastructure. The standby Grid Infrastructure upgrade can be performed in parallel with the primary if desired. 

However, the Grid Infrastructure home always needs to be on later or equal level than the Database home. Therefore upgrading Grid Infrastructure home needs to be done before a database upgrade can be performed.

Steps need to be performed in this sections are:
  • Install MGMTDB or not
  • Validate hugepage configuration for new ASM SGA requirements
  • Create a snapshot based backup of the database server partitions
  • Create the new GI_HOME directory where 12.1.0.2 will be installed
  • Prepare installation software
  • Perform 12.1.0.2 Grid Infrastructure software installation and upgrade using OUI
  • Apply latest Bundle Patch contents to Grid Infrastructure Home using 'opatch napply' (when available)
  • Change Custom Scripts and environment variables to Reference the 12.1.0.2 Grid Home

3. Install Database 12.1.0.2 Software

This section will install Oracle 12.1.0.2 RDBMS software in new Oracle Home. This section only installs Database 12.1.0.2 software into a new directory, this does not affect currently running databases, hence all the steps below can be done without downtime.

Data Guard 
  • If there is a separate system running a standby database and that system already has Grid Infrastructure upgraded to 12.1.0.2, then run these steps on the standby system separately to install the Database 12.1.0.2 software.  The steps in this section can be performed in any of the following ways:
  • Install Database 12.1.0.2 software on the primary system first then the standby system.
  • Install Database 12.1.0.2 software on the standby system first then the primary system.
  • Install Database 12.1.0.2 software on both the primary and standby systems simultaneously.

Steps need to be performed in this sections are:
  • Prepare Installation Software
  • Perform 12.1.0.2 Database Software Installation with OUI
  • Update OPatch in the new Grid Infrastructure home and New Database Home on All Database Servers
  • When available: Install Latest 12.1.0.2 Bundle Patch available for your operating system - Do Not Perform Post-Installation Steps
  • When available: Apply 12.1.0.2 Bundle Patch Overlay Patches as Specified in Document 888828.1
  • When available: Apply Customer-specific 12.1.0.2 One-Off Patches

4. Upgrade Database to 12.1.0.2

The commands in this section will perform the database upgrade to 12.1.0.2.

For Data Guard configurations, unless otherwise indicated, run these steps only on the primary database.

Steps need to be performed in this sections are:
  • Backing up the database and creating a Guaranteed Restore Point
  • Analyze the Database to Upgrade with the Pre-Upgrade Information Tool (if not done earlier)
  • Data Guard only - Synchronize Standby and Switch to 12.1.0.2
  • Data Guard only - Disable Fast-Start Failover and Data Guard Broker
  • Before starting the Database Upgrade Assistant (DBUA) stop and disable all services with PRECONNECT as option for 'TAF Policy specification'
  • Upgrade the Database with Database Upgrade Assistant
  • Review and perform steps in Oracle Upgrade Guide, 'Post-Upgrade Tasks for Oracle Database'
  • Change Custom Scripts and Environment variables to Reference the 12.1.0.2 Database Home
  • Add Underscore Initialization Parameters back that were removed earlier
  • When available: run 12.1.0.2 Bundle Patch Post-Installation Steps
  • Data Guard only - Enable Fast-Start Failover and Data Guard Broker
  • Delete Guaranteed Restore Point created before the upgrade

The database will be inaccessible to users and applications during the upgrade (DBUA) steps. Course estimate of actual application downtime is 30-90 minutes but required downtime may depend on factors such as the amount of PL/SQL that needs recompilation. 

Note that it is not a requirement all databases are upgraded to the latest release. It is possible to have multiple releases of Oracle Database Homes running on the same system. The benefit of having multiple Oracle Homes is that multiple releases of different databases can run. 

The disadvantage is that more planned maintenance is required in terms of patching. Older database releases may lapse out of the regular patching life cycle policy in time. Having multiple Oracle homes on the same node requires more disk space.

5. Post-upgrade Steps

Steps need to be performed in this sections are:
  • Remove Guaranteed Restore Point if still exists
  • DBFS only - Perform DBFS Required Updates
  • Run Exachk and validate the exacheck report
  • Verify nproc setting (CRS_LIMIT_NPROC) for Grid Infrastructure
  • Deinstall the 11.2.0.2, 11.2.0.3, 11.2.0.4 or 12.1.0.1 Database and Grid Homes
  • Re-configure RMAN Media Management Library
  • Restore settings for concurrent statistics gathering

It is always better to read updated Oracle Doc ID to make smooth upgrade in timely manner.

Oracle Exadata Growth Story...

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First exadata box V1 released in 2008 with the combination of Oracle software and HP hardware. Since that time Oracle came up with multiple exadata version with improved hardware and software. 

Oracle Exadata X5-2 was released in 2015 which was the 6th generation of exadata. Since 2008 its first release V1, exadata gone under a number of significant changes in terms of resource performance and capacity. 

You can go through our earlier post for more detailed history of Exadata.

"The Only Permanent in Life is Change"

Following graphs will give you better understanding of exadata growth from V1 to X5 release. This article will also helps to the folks who are preparing for the certification.

Oracle Exadata Release Year:

Note: Growth given based on a full rack configuration of 14 storage servers, 8 compute servers.

Growth pattern for Database server memory:

Growth pattern for Database server CPU:

Growth pattern for Storage server CPU:

Growth pattern for Storage size:

Growth pattern for Flashcache:

Growth pattern for dataload rate:

Growth pattern for connectivity:

Be connected, we will continue the success story with next version :)

You would also like:

Oracle Announced Exadata Database Machine X6-2 and X6-8

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Recently Oracle announced seventh generation Exadata Database Machine X6-2 and X6-8 with cloud enabling, more processing power, better networking and of course larger storage and memory than earlier version. In one sentence it's just awesome. 
Key features:
  • Up to 836 CPU cores and 14.6TB memory per rack for database processing
  • Up to 360 CPU cores per rack dedicated to SQL processing in storage
  • From 2 to 19 Database Servers per rack
  • From 3 to 18 Storage Servers per rack
  • Up to 460 TB of flash capacity (raw) per rack
  • Up to 1.7 PB of disk capacity (raw) per rack
  • Hybrid Columnar Compression often delivers 10X-15X compression ratios
  • 40 Gb/second (QDR) InfiniBand Network
  • Complete redundancy for high availability

You can go through the below link to get more details about this high performance Oracle Exadata Database Machine.


Happy Exadating....:)                                                              Source: www.oracle.com

The Cloud - Most Popular Word in IT

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Cloud is the most popular topic nowadays but it is not simply fashionable term in the technology, it is actually broad term. 

The cloud is something beyond the internet. It can both software and infrastructure. Where you can use technology when you need it and as long as you need it. You just pay when you use it. You do not require installing any software in your desktop at all.

Cloud models
Public cloud

A public cloud service is based on a cloud provider typically offering pre-configured and published offerings. 

They normally have an online storefront that lists all available products, configurations, options, and pricing. Because the public cloud providers are offering services to the general public and a wide variety of customers, they have implemented their own cloud management platform. The cloud platform and services offered are targeted at the widest group of potential consumers; therefore, customization of the service is normally limited.

Private cloud

Private cloud services might begin with the same basic cloud computing services
as offered by a public cloud provider, but the service can be hosted at a customer owned or contracted data center. 

Private clouds offer choices of the cloud services to be deployed, how much integration there is between services, how the management and operations are handled, and the level of security controls and accreditation.

Hybrid cloud

Hybrid cloud is a cloud computing environment which uses both private and public cloud services.

It allows to move workload between private and public clouds as computing needs and costs change. It gives businesses greater flexibility and more data deployment options.

Cloud services
SaaS

It simply provides software on demand. There is no need to install; you can directly can start using required software.

A service offering that provides one or more applications to the consumer. Applications are hosted and managed by the provider in the cloud with the consumer accessing the application services from various end-computing devices such as PCs, laptops, tablets, smartphones, or web browsers.

The consumer does not manage the underlying server farm, applications, or storage. The provider might provide the consumer a web-based self-service control panel to give the consumer some control over certain aspects of the application or user configuration. Pricing to the consumer is often based on a per seat user license with potential up-charges for additional storage or application features.

PaaS

PaaS environments provide you with an infrastructure as well as complete operational and development environments for the deployment of your applications.

IaaS

In simple terms it provides all the data center hardware needs based on the demand. 

A service that includes processing, memory, storage, and networking in the form of a VM. Consumers can deploy operating system and applications as they prefer. Cloud providers often supply OS templates as a quick-start to get the system operational quickly.

The cloud provider also handles all systems management of backend server farms, networking, storage systems, and virtualization hypervisors with the consumer managing the OS, applications, and data.

Top 15 advantages of cloud

Top cloud service providers

This is an effort by us to say THANK YOU...!!!

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A big THANK YOU to you all for your overwhelming response for our eBook Oracle Exadata Interview Questions & Answers,We were delighted to sold off 2500 copies till date. We have never thought to reach this mark when we have released this eBook. 


It was very worthwhile book for us to launch as many people put their effort to make it possible. We are sure that happiness will be brought to all the readers as a result of our efforts. If you haven't yet read this book, we thank you for exploring our website.

"Stay miles ahead of the competition"

On this special day we are very happy to inform you that we will be having a special 30% discount on eBook for limited period.This is an effort by us to say thank you for all our valued readers. This discount is available on Oracle Exadata Interview Questions and Answers eBook only.

You can use below discount coupon code at the time of purchasing to get a discount.


We appreciate the wealth of comments/appreciations we received telling us of your expert review of book and interview experience. Your feedbackmeans the world to us. 

With profound gratitude, and with hope for your continued reading pleasure.

Exadata Certification Team

How To Get Current Release Version of Exadata Components?

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Whenever we plan for patching, upgrade or migrate, knowing the current release version of exadata component is first and mandatory thing to proceed ahead. These information  also helps you while doing any configuration level changes on exadata machine.

Following commands will help you to get the current realease version of the exadata machine component.


Database Server

OS Image Version: #imageinfo



Database: $opatch lsinventory



Grid:  $opatch lsinventory


Cell Server

Software/OS Image Version: #imageinfo


Infiniband Switch

#version


Ethernet Switch

#show version


PDU

Open web console using PDU management IP. Click on module info to get the PDU firmware version


You can also refer Exadata Interview Questions and Answers eBook to get maximum success in interview.

Boost Your Earning Potential with Oracle Certification...

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Recently Certification Magazine has released the Salary Survey 2015 based on the certification credentials, which includes top 75 IT certifications. The best news is that Oracle is also one of the hottest certification now a days based on this survey. 

You will not surprise if Oracle Exadata will become the most valuable certification in Oracle technology in coming days because it includes multiple skills and now a days employer looking for multi skilled folks than single skill specialist. So grab an opportunity and earn Oracle Certification credentials to stay ahead in the competition.

Below three Oracle certification stood in the top 75 certifications in Cert Mag survey 2015.


You can go through whole survey detail by clicking on below image.



You can follow our Exadata Certification Question Bank to achieve maximum success in your Exadata certification.

Mandatory Information Required Before Extending Exadata Rack

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The current configuration information is used to plan patching requirements,configure new IP addresses, and so on. The following information should be collected as described before extending the rack.



  • Exachk report
  • Image history information using the following command
         #dcli -g ~/all_group -l root "imagehistory"> imagehistory.txt

  • Current IP addresses defined for all Exadata Storage Servers and database servers using the following command

         #cellcli -g ~/all_group -l root "ifconfig"> ifconfig_all.txt

  • Information about the configuration of the cells, cell disks, flash logs, and IORM plans using the following commands

        #dcli -g ~/cell_group -l root "cellcli -e list cell detail"> cell_detail.txt

        #dcli -g ~/cell_group -l root "cellcli -e list physicaldisk detail"> \
        physicaldisk_detail.txt

        #dcli -g ~/cell_group -l root "cellcli -e list griddisk attributes \
        name,offset,size,status,asmmodestatus,asmdeactivationoutcome"> \           griddisk.txt

        #dcli -g ~/cell_group -l root "cellcli -e list flashcache detail"> \
        fc_detail.txt

        #dcli -g ~/cell_group -l root "cellcli -e list flashlog detail"> fl_detail.txt

        #dcli -g ~/cell_group -l root "cellcli -e list iormplan detail"> \
        iorm_detail.txt

  • HugePages memory configuration on the database servers using the following command

        #dcli -g ~/dbs_group -l root "cat /proc/meminfo | grep 'HugePages'">\          hugepages.txt

  • InfiniBand switch information using the following command

        #ibswitches > ibswitches.txt

  • Firmware version of the Sun Datacenter InfiniBand Switch 36 switches using the

        #nm2version command on each switch.

  • The following network files from the first database server in the rack

         – /etc/resolv.conf
         – /etc/ntp.conf
         – /etc/network
         – /etc/sysconfig/network-scripts/ifcfg-*

  • Any users, user identifiers, groups and group identifiers created for cluster-managed services that need to be created on the new servers

         – /etc/passwd
         – /etc/group

  • Output of current cluster status using the following command

         $crsctl stat res -t > crs_stat.txt

  • Patch information from the Grid Infrastructure and Oracle homes using the following commands. The commands must be run as Grid Infrastructure home owner, and the Oracle home owner

       $/u01/app/oracle/product/11.2.0/dbhome_1/OPatch/opatch lsinventory -oh        GRID_HOME -detail -all_nodes > opatch_grid.txt

       $/u01/app/oracle/product/11.2.0/dbhome_1/OPatch/opatch lsinventory -oh        ORACLE_HOME -detail -all_nodes >> opatch_oracle.txt

What is Cell Efficiency Ration in Exadata?

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If you have observed, when we invoke CELLCLI utility, it use to display Cell Efficiency Ratio in banner. Example given below.


So what does cell efficiency ratio indicate?

It is the ratio between data accessed by the storage cell and data processed by the database for the cell. Higher the value greater the I/O savings as a result of offloading.

The Cell Efficiency Ratio is same as the value displayed for offloadEfficiency in CELLCLI>LIST CELL DETAIL as below


Then the ratio of the total MB accessed on the cell to the MB accessed on the host (for the cell) is computed every minute that CELLSRV is active by Management Server (MS). 

It is difficult to explain as there is no manual intervention we can do nor we can fetch detailed result of it. We can use it for reference purpose only as there is no practical value from performance perspective of Exadata. 

What Is Exafusion ?

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Exafusionallows database processes to read and send Oracle Real Applications Cluster (Oracle RAC) messages directly over the Infiniband network bypassing the overhead of entering the OS kernel, and running the normal networking software stack.

Benefits
  • Lower latency
  • Improve response time
  • Higher throughput direct to wire block transfers between Oracle Real Application Clusters (Oracle RAC) instances
  • Reduced CPU utilization and better scale-out performance
  • Exafusion is especially useful for OLTP applications because per message overhead is particularly apparent in small OLTP messages. It helps small messages by bypassing OS network layer overhead. 

Parameter
  • EXAFUSION_ENABLED parameter is used to enable or disable the Exafusion accelerate cache fusion protocol feature, which is available on the Linux operating system of Oracle Exadata Database Machine only.
  • Exafusion is disabled by default.
  • To enable Exafusion, set the EXAFUSION_ENABLED initialization parameter to 1. To disable Exafusion, set the EXAFUSION_ENABLED initialization parameter to 0.
  • This parameter cannot be set dynamically. It must be set before instance startup.

Prerequisites and Limitations
  • Oracle Storage Server Software release 12.1.2.1.1 or later is required.
  • Mellanox ConnectX-2 and ConnectX-3 Host Channel Adapters (HCAs) are required.
  • Oracle Unbreakable Enterprise Kernel 2 Quarterly Update 5 (UEK2QU5) kernels (2.6.39-400.2nn) or later are required.
  • The Exafusion feature does not support mixed mode operation on an Oracle RAC cluster. Either all the instances in an Oracle RAC cluster must have the feature enabled or none.
  • Rolling upgrades of a non-Exafusion enabled Oracle RAC cluster to Exafusion are not supported.
  • Exafusion is available only on the Linux operating system of Oracle Exadata Database Machine
  • It is not supported on any non-engineered system or SPARC Super Cluster (SSC). If you set the EXAFUSION_ENABLED parameter on a non-supported platform, then the instance will be prevented from starting up, and an ORA-00439: The specified feature is not enabled: string error message is generated.
  • This initialization parameter is available starting with Oracle Database 12c Release 1 (12.1.0.2) Bundle Patch 11 (BP11).
 Source: https://docs.oracle.com

VNC Server Blank Gray Screen - Exadata Linux

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Recently faced issue of VNC server while we have upgraded exadata operating system. 

We have installed VNC server manually on compute node and tried to start the VNC server. Well, it was starting without any issue but it was giving only gray screen without console output. When we have checked VNC server log file, it was showing  below error.

Log file: /home/oracle/.vnc/dbadm01.test.com:1.log

/root/.vnc/xstartup: line 28: xterm: command not found

This error is indicating that xterm rpm is missing. After installing xterm rpm everything was working fine.

Related errors if respective RPMs are not installed.

/root/.vnc/xstartup: line 27: xsetroot: command not found
/root/.vnc/xstartup: line 29: twm: command not found
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