What is HARD in Oracle Exadata?

Hardware Assisted Resilient Data (HARD)

• HARD will prevent data corruptions from being written to storage disks.
• Oracle database validates and add protection while sending data to the storage server.
• Whenever data will go to storage server , first it will check if there is any data corruption. If it found the corrupted data , it would stops corrupted data from being written to disk.
• Previously or in non-Exadata hardware it's not possible to prevent corrupted data to be written on to the storage and that was major reason for database corruption in many cases which Oracle has eliminated with the use of storage software which has been introduced in Exadata storage cell.
• There is nothing to set on Database level or storage level as  HARD handle corruption transparently which also included for ASM rebalance.

Script to Find Hidden Parameters in Oracle

SELECT
  x.ksppinm name,
  y.ksppstvl VALUE,
  decode(ksppity,
    1,   'BOOLEAN',
    2,   'STRING',
    3,   'INTEGER',
    4,   'PARAMETER FILE',
    5,   'RESERVED',
    6,   'BIG INTEGER',
    'UNKNOWN') typ,

Exadata Bundle Patch Bug on 11.2.0.3.18ExadataDatabase

One of our team member has shared resolution of bug while patching on Exadata storage server.

Below is the full story

System landscape:

Exadata Machine = Exadata 1/8th Rack X3-2 machine

Platform = Linux x86-64 

Product = Oracle Database 

Version = 11.2.0.3.18ExadataDatabase 

Here we are doing prechek to apply bundle patch on Exadata. ((Quarterly Full Stack Download Patch (QFSDP) Oct 2014)

Go to the patch directory and first execute cleanup to clean previous patch manager utility.

Here patch directory for storage cell is "/bpatch/19625719/Infrastructure/11.2.3.3.1/ExadataStorageServer_InfiniBandSwitch/patch_11.2.3.3.1.140708/"

#./patchmgr -cells /root/cellgroup -cleanup                                                     
2014-12-06 12:01:05 +0800        :Working: DO: Cleanup ...
2014-12-06 12:01:45 +0800        :SUCCESS: DONE: Cleanup

Executing pre-check through patchmgr utility 

#./patchmgr -cells ~/cellgroup -patch_check_prereq -rolling

2014-12-06 12:09:47 +0800        :Working: DO: Initialize files, check space and state of cell services. Up to 1 minute ...
2014-12-06 12:10:24 +0800        :SUCCESS: DONE: Initialize files, check space and state of cell services.
2014-12-06 12:10:24 +0800        :Working: DO: Copy, extract prerequisite check archive to cells. If required start md11 mismatched partner size correction. Up to 40 minutes ...
2014-12-06 12:10:38 +0800 Wait correction of degraded md11 due to md partner size mismatch. Up to 30 minutes.
2014-12-06 12:10:40 +0800        :SUCCESS: DONE: Copy, extract prerequisite check archive to cells. If required start md11 mismatched partner size correction.
2014-12-06 12:10:40 +0800        :Working: DO: Check prerequisites on all cells. Up to 2 minutes ...
2014-12-06 12:12:36 +0800        :SUCCESS: DONE: Check prerequisites on all cells.
2014-12-06 12:12:36 +0800        :Working: DO: Execute plugin check for Patch Check Prereq ...
2014-12-06 12:12:36 +0800 :INFO: Patchmgr plugin start: Prereq check for exposure to bug 17854520 v1.1. Details in logfile /bpatch/19625719/Infrastructure/11.2.3.3.1/ExadataStorageServer_InfiniBandSwitch/patch_11.2.3.3.1.140708/patchmgr.stdout.
2014-12-06 12:12:36 +0800 :INFO: This plugin checks dbhomes across all nodes with oracle-user ssh equivalence, but only for those known to the local system. dbhomes that exist only on remote nodes must be checked manually.
2014-12-06 12:12:55 +0800 :WARNING: ACTION REQUIRED: Required fix for bug 17854520 not found in dbhome /u01/app/oracle/product/11.2.0.3/dbhome_1 on dbadm01. Install the fix before performing rolling cell patching.
2014-12-06 12:12:55 +0800 :WARNING: ACTION REQUIRED: Required fix for bug 17854520 not found in dbhome /u01/app/oracle/product/11.2.0.3/dbhome_1 on dbadm02. Install the fix before performing rolling cell patching.
2014-12-06 12:12:55 +0800 :WARNING: Patchmgr plugin complete: Prereq check failed - fix for bug 17854520 is required
2014-12-06 12:12:56 +0800        :FAILED: Details in files <cell_name>.log /bpatch/19625719/Infrastructure/11.2.3.3.1/ExadataStorageServer_InfiniBandSwitch/patch_11.2.3.3.1.140708/patchmgr.stdout, /bpatch/19625719/Infrastructure/11.2.3.3.1/ExadataStorageServer_InfiniBandSwitch/patch_11.2.3.3.1.140708/patchmgr.stderr
2014-12-06 12:12:56 +0800        :FAILED: DONE: Execute plugin check for Patch Check Prereq.
[ERROR] Patch prerequisite checks failed. Please run cleanup before retrying.

As per above output, pre-check has not been completed successfully and we need to apply bug fix 17854520 on Grid and RDBMS home.


Now let's do the exercise to resolve this issue.

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

How to install VNC Server on Oracle Exadata?

VNC is an excellent tool to connect GUI interface.

It also has an advantage of running task remotely and keep them alive even once your network connection to a remote VNC disconnected. 

This is a quite useful if you run some important GUI updates, which may take several hours and you do not want to kill this update simply by loosing a network connection which can be accessed by VNC viewer from our work station.

Exadata doesn't come with GUI configured so we can use third party tool to get GUI from Exadata or can configure VNC server on top of Database server.

To install and configure VNC-Server we have to install it separately as it is not a part of Oracle ACS team who do the Exadata initial setup.

Here we have given step by step guide to install and configure VNC-Server on Exadata.

There are multiple method to install VNC server like yum or manual RPM installation.

We have explained here VNC server installation with manual RPM installation.

Click on image to enlarge....

1. List of RPM with dependency which required to install VNC server.