Newly Released: Oracle Exadata X8-2

This post is bit late but important if still you are not updated.

Recently Oracle announced Latest Oracle Exadata X8 which is specially design to expand more capacity in terms of storage by increasing the size of storage disk.

There no huge changes compare to Exadata X7. The major change is the size of disk from 10TB to 14TB which will ultimately help to reduce cost as Oracle Exadata storage includes license cost for storage disk also.

There are not change in number of CPU but clockspeed of CPU has been increased in newer version. There is no change in size of memory.

Third type of storage has been introduced, Storage Server XT. This is a storage node without flash cards and with less memory and only a single CPU. This type of node is intended for long term data storage for archiving purposes. It will cost considerably less than the regular storage nodes.

Check out this data sheet for the full specification overview: 

https://www.oracle.com/a/ocom/docs/engineered-systems/exadata/exadata-x8-2-ds.pdf

Tips To Clear Oracle Exadata Certification Exam

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. 

Capacity On Demand In Exadata Database Machine

Oracle has introduced capacity on demand on Exadata Database Machine so let's understand what is capacity on demand?

General Definition of COD:

Capacity on demand (COD) is a purchasing option that allows companies to receive equipment with more computer processing, storage, or other capacity than the company needs at the time of purchase, and have that extra capacity remain unused and unpaid for until the company actually requires it.

The number of active cores can be increased when additional capacity required is called capacity on demand.

Additional cores can be increased in 2-cores increment in X4-2 and X5-2 where as in X4-8 it can be increased in 8-cores increment.

Advantage:

Let's take an Example of database machine. When customer buy Exadata 1/8th Rack, only half of the cores would be enabled and half of them would be disabled so when customer's business expands and they required more computing power than they don't required to look around to increase it as vendor has already provided additional capacity which can be enabled at any time so in this case customer do not required to pass from purchasing procedure or any other hazardous which are time consuming. 

Simply they can enable it themselves whenever required.

umount: /u01 device is busy

Recently we faced this error while un-mounting /u01 file system.

You can get this error in two case either some one is logged in into the file system or some process is using this file system.

We have checked that no one is using /u01 file system now only one option was there , some process is using /u01 file system which is not allowing us to un-mount it.

We can check with below command that which processes are associated with /u01 file system.

How to disable/enable CPUs in Linux ?

It's quite interesting to know how to disable and enable CPU core in Linux in different scenario.

Thought came from Exadata architecture as Exadata 1/8th Rack comes with 16 cores but only half of the CPUs will be enabled on the DB server, that's why we have to pay Oracle licence cost for half core only.

This enabling and disabling can be controlled by resource control utility which comes with Exadata, so what we can do to enable or disable cpu core in non Exadata server?

We have performed this test on test server which has four CPU cores.

Step 1: Check Total Available CPU

There are multiple method to check it, we have checked it with TOP utility which give you better understanding. It shows 4 cpu cores are available.

Things To Do Before Applying Bundle Patch On Exadata

One of our reader asked us, what we should take care before applying the bundle patch on Exadata, so thought to write this article where we have mentioned some points based on our patching experience, we can say it's part of bundle patch pre-preparation.

Missing of single point can lead you to difficult stage which we can eliminate by planing better.

               "Always plan for worst to do the best"

• Make sure that you have backup plan for Exadata box connectivity in case you are doing things remotely
• Install VNC client on your workstation
• Install VNC server on Exadata in case if you required GUI. You can also use Xmanager and Xming to take GUI from your workstation

Linux Server Performance Analyzer Utilities

If there is any Linux performance issue we mostly go to Google and find commands to analyze the performance but multiple time it's difficult to find it when we required some specific details so, we have tried here to place all the Linux performance utility which can help you to analyze the Linux server performance.

There are multiple utilities available to analyse Linux server. Which includes CPUs, Memory, I/O, disk, network analysis.

Utility	Discription
free	Displays free and used memory.
iostat	Displays disk I/O statistics.
netstat	Reports on network statistics.
mpstat	Reports CPU statistics.
vmstat	Monitors processes, CPU, memory, or disk I/O bottlenecks.
ps	Identifies highest CPU- and memory-consuming sessions. Used to identify Oracle
sar	Displays CPU, memory, disk I/O, and network usage, both current and historical
top	Identifies sessions consuming the most resources.
watch	Periodically runs another command.
du	Displays disk usage.
df	Reports on free disk space.

                                              How to calculate IOPS in Exadata ?

Oracle Database In-Memory (DBIM)

Let's first understand why DBIM is revolutionized...

Generally Organization keeps different database for Reporting and Application Transaction because of the performance issues so whenever any transactions happen to the Application Transaction database it will immediately replicate to report database which help to get up date data while fetching report from the reporting database.

Business don't want to access same database for reporting and transaction because of the performance impact on single DB as mixed workload can slow the database and  that's why they prefer to keep separate database for both activity which gives overhead of h/w & s/w management, required more resources to handle both environment and ultimately it will  increase TCO at the end of day.

To overcome from this situation Oracle comes with DBIM (Database In Memory) which keeps frequently accessed data in memory to get faster response and decrease the response time by eliminating disk IO. It will store Database in storage only but it will store most accessible data in memory which gives faster response compare to read from disk. We can also influence object which we want to keep in memory.

Exadata Dictionary Views

Listed down some Exadata views which can help you to get Exadata related statistics

Get Cell Definition

V$CELL 

GV$CELL 

Exadata cell effectiveness and statistics

V$SYSSTAT 

V$SEGMENT_STATISTICS 

V$SQL 

Historical view of the types and frequencies of the requests being run by a cell.

V$CELL_REQUEST_TOTALS 

Cell Performance Statistics

V$CELL_STATE 

Display Exadata Cell Threads

V$CELL_THREAD_HISTORY

Backup Related View

V$BACKUP_DATAFILE 

Useful Files in Solaris

Message log:  /var/adm/messages

Tape driver configuration file:  /kernel/drv/st.conf

Disk driver configuration file:  /kernel/drv/sd.conf

File defining filesystems to mount:  /etc/vfstab

Kernel configuration parameters:  /etc/system

Names and IP addr of machines:  /etc/hosts

Default Port Numbers:  /etc/services

                                    Analyze Linux Server Performance

How to check that database is running on Exadata?

All the DBA don't get chance to work on Exadata as only DMA would have access to the Exadata so , if you are a DBA and want to know that whether your database is running on Exadata or not than you can check with below query.

If this query gives the output >0 than database is running on Exadata.

SQL>select count(*) from (select distinct cell_name from gv$cell_state);

COUNT(*)

------------

         3

It means database is running on 1/8th Exadata as 3 tells you the number of cells available on database machine.

By executing "select distinct cell_name from gv$cell_state" you will get cell IP details.

Password Aging in Linux

Disable Password Aging

#chage -M 99999 user_name

To get password expiration information

#chage -l user_name

To change aging

# chage -M 60 -m 7 -W 7 user_name

Here,

Minimum_days (M): The minimum number of days required between password changes i.e. the number of days left before the user is allowed to change his/her password.

Maximum_days(m): The maximum number of days the password is valid (after that user is forced to change his/her password).

Warn (W) : The number of days before password is to expire that user is warned that his/her password must be changed.

Oracle Exadata vs SAP HANA

We have provided some major difference between SAP HANA and Oracle Exadata. 

Even Exadata is not comparable with HANA than also we have tried to conclude it based on materials and documentation available in the market.

Oracle Exadata	SAP HANA
SAP HANA is an in-Memory Appliance.	SAP HANA is an in-Memory Appliance.
Oracle Exadata is based on Oracle servers, storage, networking, and software– all engineered and optimized to work together. It’s meant for Mixed workloads, i.e OLTP,DW	SAP HANA and partner solutions powered by the SAP HANA in-memory software. There are only a limited number of specialized SAP applications that run on HANA
We can use existing Oracle licences with Exadata	If we move to HANA, it's required to buy new licences as existing licences would not be reused
Oracle Exadata is delivered pre-configured, pre-tested and pre-optimized, with all necessary software, storage, hardware,and interconnect to lower total cost of ownership and provide quick time to value. Oracle Exadata is sold, delivered, and supported as a single-vendor solution with quick time-to-resolution.	SAP HANA relies on third-party compute, network,and storage vendors. Multiple points of support lead to longer downtimes and higher total cost of ownership. No single vendor is accountable for the solution's service-level agreements and due to its complexity, HANA deployments typically require a significant amount of effort.
Exadata can be used for any type of workload for any application which is running with Oracle Database	HANA is limited to SAP BW only. It doesn't support any other application
Exadata is capable for all type of workload so customer can consolidate multiple database on single machine.	SAP HANA runs only single application. It doesn't support multiple workload as well non sap DBs
Exadata comes with built in security	HANA don't have any encryption, auditing , compliance monitoring or any security certification
Oracle Exadata is enough smart to use RAM, Flash and Storage	HANA puts everything on memory
Exadata is single vendor optimized machine	HANA comes as an assemble hardware
Exadata is pre configured with HA and single point of hardware failure	HANA has limited capabilities in backup and recovery area. Also there is no failover solution as well disaster recovery solution
We can use IORM and instance caging in Exadata to prioritize the I/Os.	There is no features available to prioritize I/O in HANA
TCO is less compare to HANA	TCO is high compare to Exadata
Only Exadata DBA is required to manage Exadata	Multiple resource required to manage HANA

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

Oracle EM12c Quick Reference

OEM 12c comes with many exciting features compare to OEM 11g. That's why there are many options in navigation pane and cloud control panel of OEM12c and It's very difficult to remember each of them.

Managing Exadata with OEM 12c

Many times it happens like we configure something and after sometime if we have to do the same activity then it's very difficult to remember the options from where we have configured earlier and the same effort we have to give even though we know how to do.

Here we have just given list of options available with navigation pane in OEM12c which will act as Quick Reference for EM12c. Hope this will help you.

Click on image to enlarge....

On OEM12c home page we get below navigation pane on top of the screen.

Navigation menu located at top of the left side screen.

It used for navigating the console. There are four menus in navigation pane as below.

Enterprise Menu

It is available to get the view of overall system.Options in Enterprise will give you wide options for monitoring and make it standardize.

Target Menu

It gives access to the configured targets.

Integrate Oracle Support with OEM12c

Procedure to integrate Oracle Support with OEM12c

1. First set the proxy if any, otherwise you can keep as it is like no proxy

Go to


Setup -> Proxy Settings -> My Oracle Support


Click to enlarge

Provide proxy settings:

Test the proxy setting:

Apply Proxy:

2. Apply your oracle credentials which you want to integrarte with EM

Oracle Block Change Tracking (BCT)

Block change tracking records the modified blocks since last backup and stores this logs in block change tracking file.

During backups,  RMAN uses this log file to identify the specific blocks (changed block) that must be backed up.

Benifits: BCT improves RMAN backup performance as it would not required to scan whole datafiles to detect changed blocks. It will only see the changed block through block change tracking files and take the back up that clock.

Whenever data blocks change, the Change Tracking Writer (CTWR) background process tracks the changed blocks in a private area of memory. 

When a commit is issued against the data block, the block change tracking information is copied to a shared area in Large Pool called the CTWR buffer.

During the checkpoint, the CTWR process writes the information from the CTWR RAM buffer to the block change-tracking file.

To see the status of BCT Status

How to change OEM 12c Agent Port ?

Whenever we install EM agent, it will use default port at time of installation on target host. If we need to modify the port then we can follow below steps to change the port number.

Stop the EM Agent
$ $AGENT_HOME/bin/emctl stop agent

Modify the $AGENT_HOME/sysman/config/emd.properties file in the EM Agent home directory:

For example:
EMD_URL=http://example.com:3872/emd/main

Modify the <port number> in the EMD_URL property so the EM Agent uses a new unused port on the target host.

EMD_URL=http://example.com:3883/emd/main

Start the EM Agent.

$ $AGENT_HOME/bin/emctl start agent

Check the EM status

Exadata Patching Strategy

Let's have an overview of Exadata Machine patching.

1. Check latest patches available on Oracle note ID - 888828.1 
2. Download the required patches
3. Review the patch README file
4. Make step by step plan to apply patch for all the component
5. Run Exachk utility before the patch application, analyse the report and correct wherever it's required.
6. Automate the patch application process based on rolling or non-rolling method
7. Apply the patch

Resource Control in Exadata

We can check enabled resources (CPUs, RAM) with below command on exadata.

Sample output from one storage cell of Exadata 1/8th Rack

[root@cell01 ~]# /opt/oracle.SupportTools/resourcecontrol -show

[INFO] Validated hardware and OS. Proceed.

[SHOW] Number of cores active per socket: 3

[SHOW] Number of harddisks active - 6.

[SHOW] Number of flashdisks active - 8.

1/8th Exadata Rack comes with same hardware as quarter rack, but only half of the resources would be enabled on each 1/8th storage cell So, if in future if we need to upgrade 1/8th rack to quarter rack then we can use this utility to enable rest all the resources.

Above example shows all the enabled resources on one storage cell.

Exadata OneCommand Utility Steps

Onecommand:

• Onecommand utility is used to configure the Exadata machine based on given information through OEDA by customer.
• Also whatever steps are performed by oncecommand can be changed based on the customer's required configuration and environment.
• All the steps runs sequentially and each step must be completed before execution of next step.
• Steps can be run individually as well as in one shot with single command.

Below are the steps which need to be executed through onecommand utility. 

Step 0: Validate the environment.

Step 1: Create work directory

Step 2: Unzip files

Step 3: Setup SSH for the root user

Step 4: Update the /etc/hosts file

Step 5: Create the cellip.ora and cellinit.ora files

Step 6: Validate the InfiniBand network

Step 7: Update the cell software

Step 8: Validate the cells

Step 9: Check RDS using the ping command

Step 10: Run CALLIBRATE on the cells