Presenting at Cloud day event of North India Chapter of AIOUG

I will be presenting a session titled “An 18 pointers guide to setting up an Exadata machine” at Cloud Day being organized by North India chapter of AIOUG. Vivek Sharma is doing multiple sessions on various cloud and performance related topics. You can register for the event here 


ksplice kernel updates and Exadata patching

If you have installed some one off ksplice fix for kernel on Exadata, remember to uninstall it before you do a kernel upgrade  eg regular Exadata patching. As such fixes are kernel version specific so they may not work with the newer version of the kernel. 

Exadata Storage Server Patching in 18.1.1 and Above

One of the cool new features that was introduced with was a subtle change in the Exadata storage server patching process.  While not required, this new functionality removes the need to use patchmgr to drive Exadata storage server patches.  In Juan Loaiza’s Open World session on new Exadata features, this slide jumped out to me:

While this slide may look like marketing fluff, this new feature turns out (more...)

Exadata Flash Cache enabled for Write Back

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 (more...)

Thoughts About the Exadata X7-2 Launch

Last week’s Oracle Open World conference included many different announcements – one that impacts my work was the release of a new generation of Exadata machines – this time, the X7-2. If you’ve followed Exadata development over the years, there has been a typical set of features that come in with each release:

  • Increase in CPU core count
  • Increase in disk storage (typically 2x)
  • Increase in flash storage (typically 2x)
  • New software features

The screenshot (more...)

Important Change for Grid 12.2 Upgrade and MGMTDB

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 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 (more...)

New workshop "Exadata For Developers"

Just a short note that I've developed a new two day course that covers all relevant features that a database application developer should know when dealing with the Oracle Exadata Database Machine platform.

It covers in detail Smart Scans, the Exadata Flash Cache, Hybrid Columnar Compression and all surrounding features like Storage Indexes, (serial) direct path reads etc. etc.. Of course it also includes features that were added in 12c, like Attribute Clustering and Zone (more...)

Failed to create voting files on disk group RECOC1

Long story short, faced this issue while running OneCommand for one Exadata system. The step (Initialize Cluster Software) was failing with the following error on the screen

Checking file on node
Error: Error running root scripts, please investigate…
Collecting diagnostics…
Errors occurred. Send /u01/onecommand/linux-x64/WorkDir/ to Oracle to receive assistance.

Doesn’t make much sense. So let us check the log file of this step

2017-04-27 (more...)

OneCommand Step 1 error

Hit this silly issue while doing an Exadata deployment for a customer. Step 1 was giving the following error:

ERROR: configured on as dm01dbadm02 does not match expected value

I wasn’t able to make sense of it for quite some time until a colleague pointed out that the reverse lookup entries should be done for FQDN only. As it is clear in the above message (more...)

Exadata Upgrade to – The Missing Step

I decided this week to be a little brave and upgrade one of the Enkitec Exadata racks to  I installed the Exadata image a few weeks ago, and have been waiting for a chance to upgrade clusterware to 12.2.  Thankfully, Oracle provides a very good note for this, but I did hit one large snag that should be documented.

The process for upgrading GI to 12.2 (more...)

Oracle Database 12.2 released for Exadata on-premises

We live in exciting times, Oracle Database 12.2 for Exadata was released earlier today.

The 12.2 database was already available on the Exadata Express Cloud Service and Database as a service for a few months now.

Today, it has been released for Exadata on-premises, five days earlier than the initial Oracle announcement of 15th Feb.

The documentation suggests that to run 12.2 database you need to run at least 12.1.2. (more...)

Exadata Cell Patching – USB I/O Errors

I was playing around with the Exadata X2-2 in the Enkitec lab this weekend, and hit an interesting issue when patching the storage servers.  We were taking the system up to version for testing purposes.  I fired off the patchmgr script, and one of the storage servers failed when beginning the first phase of the patching cycle:

[root@enkdb03 patch_12.]# ./patchmgr -cells cell_group -patch -ignore_alerts

Upgrading to Exadata or later – mind the 32bit packages

This might not be relevant anymore, shame on me for keeping it draft for few months. However, there are still people running an older versions of Exadata storage software and it might still help someone out there.

With the release of Exadata storage software, Oracle announced that some 32bit (i686) packages will be removed from the OS as part of the upgrade.

This happened to me in the summer last (more...)

onecommand fails to change storage cell name

It’s been a busy month – five Exadata deployments in the past three weeks and new personal best – 2x Exadata X6-2 Eighth Racks with CoD and storage upgrade deployed in only 6hrs!

An issue I encountered with the first deployment was that onecommand wouldn’t change the storage cells names. The default cell names (not hostnames!) are based on where they are mounted within the rack and they are assigned by the elastic configuration (more...)

Unable to perform initial elastic configuration on Exadata X6

I had the pleasure to deploy another Exadata in the first week of 2017 and got my first issue this year.

As we know starting with Exadata X5, Oracle introduced the concept of Elastic Configuration. Apart from allowing you to mix and match the number of compute nodes and storage cells they have also changed how the IP addresses are assigned on the admin (eth0) interface. Prior X5, Exadata had default IP addresses set at (more...)

SLOB 2.3 Data Loading Failed? Here’s a Quick Diagnosis Tip.

The upcoming SLOB 2.4 release will bring improved data loading error handling. While still using SLOB 2.3, users can suffer data loading failures that may appear–on the surface–to be difficult to diagnose.

Before I continue, I should point out that the most common data loading failure with SLOB in pre-2.4 releases is the concurrent data loading phase suffering lack of sort space in TEMP. To that end, here is an example of (more...)

Exadata memory configuration

Read this post if your Exadata compute nodes have 512/768GB of RAM or you plan to upgrade to the same.

There has been a lot of information about hugepages and I wouldn’t go into too much details. For efficiency, the (x86) CPU allocates RAM by chunks (pages) of 4K bytes and those pages can be swapped to disk. For example, if your SGA allocates 32GB this will take 8388608 pages and given that Page Table (more...)

OTN Appreciation Day:

In the wake of the great hospitality shown by the OTN crew at Open World, Tim Hall thought that getting the community together for a series of “OTN appreciation” blogs would be a good way to show our thanks back.

Thinking about tools provided by Oracle that make my life easier, my mind went to  This tool helps automate many of the tedious tasks that must be performed when performing an OS update on an Exadata compute (more...)

How to enable Exadata Write-Back Flash Cache

Yes, this is well-known and the process has been described in Exadata Write-Back Flash Cache – FAQ (Doc ID 1500257.1) but what the note fails to make clear is that you do NOT have to restart cell services anymore hence resync the griddisks!

I had to enable the WBFC many times before and every time I’d restart the cell services, as note suggests. Well, this is not required anymore, starting with 11.2.3. (more...)

Extending an Exadata Eighth Rack to a Quarter Rack

In the past year I’ve done a lot of Exadata deployments and probably half of them were eighth racks. It’s one of those temporary things – let’s do it now but we’ll change it later. It’s the same with the upgrades – I’ve never seen anyone doing an upgrade from an eighth rack to a quarter. However, a month ago one of our customers asked me to upgrade their three X5-2 HC 4TB units from (more...)