How Many ASM Disks Per Disk Group And Adding vs. Resizing ASM Disks In An All-Flash Array Environment

I recently posted a 4-part blog series that aims to inform readers that, in an All-Flash Array environment (e.g., XtremIO), database and systems administrators should consider opting for simplicity when configuring and managing Oracle Automatic Storage Management (ASM).

The series starts with Part I which aims to convince readers that modern systems, attached to All-Flash Array technology, can perform large amounts of low-latency physical I/O without vast numbers of host LUNs. Traditional storage (more...)

Resizing ASM Disks On Modern Systems. Real Application Clusters Doesn’t Make It Any More Difficult. An XtremIO Example With RAC.

My recent post about adding space to ASM disk groups by resizing them larger, as opposed to adding more disks, did not show a Real Application Clusters example. Readers’ comments suggested there is concern amongst DBAs that resizing disks (larger) in a RAC environment might somehow be more difficult than in non-RAC environments. This blog entry shows that, no, it is not more difficult. If anything is true it is that adding disks to ASM (more...)

Stop Constantly Adding Disks To Your ASM Disk Groups. Resize Your ASM Disks On All-Flash Array Storage. Adding Disks Is Really “The Y2K Way.” Here’s Why.

This blog post is centered on All-Flash Array(AFA) technology. I mostly work with EMC XtremIO but the majority of my points will be relevant for any AFA. I’ll specifically call out an array that doesn’t fit any of the value propositions / methods I’m writing about in this post.

Oracle Automatic Storage Management (ASM) is a very good volume manager and since it is purpose-built for Oracle Database it is the most popular storage presentation (more...)

Host I/O Queue Depth with XtremIO and SLOB Session Count. A Granular Look.

In my recent post about aggregate host I/O queue depth I shared both 100% SQL SELECT and 20% SQL UPDATE test results (SLOB) at varying LUN (ASM disk) counts. The LUNs mapped to XtremIO volumes but the assertions in that post were really applicable in most All-Flash Array situations.

I received quite a bit of email from readers about the granularity of session counts shown in the charts in that post. Overwhelmingly, folks asked to (more...)

Yes, Host Aggregate I/O Queue Depth is Important. But Why Overdo When Using All-Flash Array Technology? Complexity is Sometimes a Choice.

That’s The Way We’ve Always Done It

I recently updated the EMC best practices guide for Oracle Database on XtremIO. One of the topics in that document is how many host LUNs (mapped to XtremIO storage array volumes) should administrators use for each ASM disk group. While performing the testing for the best practices guide it dawned on me that this topic is suitable for a blog post. I think too many DBAs are still (more...)

Introducing a VCE White Paper. Consolidating SAP, SQL Server and Oracle Production/Test/Dev/OLTP and OLAP Into a Single XtremIO Array with VCE Converged Infrastructure.

This is just a short blog post to direct readers to a fantastic mixed-workload and heterogeneous database consolidation Proof of Concept. This VCE paper should not be missed. I assert that the VCE converged infrastructure platforms–most notably the Vblock 540–are the best off-the-shelf solution for provisioning XtremIO storage array all-flash storage to large numbers of hosts each processing vastly differing workloads (production,test/dev,OLTP,OLAP).

This paper is full of useful information. It explains the XtremIO 24:1 data (more...)

Expecting Sum-Of-Parts Performance From Shared Solid State Storage? I Didn’t Think So. Neither Should Exadata Customers. Here’s Why.



Last month I had the privilege of delivering the key note session to the quarterly gathering of Northern California Oracle User Group. My session was a set of vignettes in a theme regarding modern storage advancements. I was mistaken on how much time I had for the session so I skipped over a section about how we sometimes still expect systems performance to add up to a sum of its parts. This blog post (more...)

You Scratch Your Head And Ponder Why It Is You Go With Maximum Core Count Xeons. I Can’t Explain That, But This Might Help.

Folks that have read my blog for very long know that I routinely point out that Intel Xeon processors with fewer cores (albeit same TDP) get more throughput per core. Recently I had the opportunity to do some testing of a 2-socket host with 6-core Haswell EP Xeons (E5-2643v3) connected to networked all-flash storage. This post is about host capability so I won’t be elaborating on the storage. I’ll say that it was block storage, (more...)

Yes, You Must Use CALIBRATE_IO. No, You Mustn’t Use It To Test Storage Performance.

I occasionally get questions from customers and colleagues about performance expectations for the Oracle Database procedure called calibrate_io on XtremIO storage. This procedure must be executed in order to update the data dictionary. I assert, however, that it shouldn’t be used to measure platform suitability for Oracle Database physical I/O. The main reason I say this is because calibrate_io is a black box, as it were.

The procedure is, indeed, documented so it can’t (more...)

Is SLOB AWR Generation Really, Really, Really Slow on Oracle Database Yes, Unless…

If you are testing SLOB against and find that the AWR report generation phase of is taking an inordinate amount of time (e.g., more than 10 seconds) then please be aware that, in the SLOB/awr subdirectory, there is a remedy script rightly called 11204-awr-stall-fix.sql.

Simply execute this script when connected to the instance with sysdba privilege and the problem will be solved.


Filed under: oracle

Performance Data Visualization for SLOB. The SLOB Expert Community is Vibrant!

Thanks to Nikolay Savvinov (@oradiag) for his excellent post on how to wrap his scripts around the SLOB test driver ( to capture and produce performance data visualization graphs.  I recommend a visit to his post here:

Performance Data Visualization with SLOB


As always, the link for SLOB is: Obtain the SLOB Kit and Helpful Information Here

Filed under: oracle

Little Things Doth Crabby Make – Part XVIV: Enterprise Manager 12c Cloud Control Install Problem.

This is a short post to help out any possible “googlers” looking for an answer to why their EM Cloud Control install is failing in the make phase with

Note, this EM install was taking place on an Oracle Linux 7.1 host.

The following snippet shows the text that was displayed in the dialogue box when the error was hit:

INFO: 11/12/15 12:10:37 PM PST: ----------------------------------
INFO: 11/12/15  (more...)

Oracle OpenWorld 2015. Additional Attractions to Consider: OakTable World and EMC Rocks Oracle OpenWorld.

This is a quick blog entry to to share some information with readers who are attending Oracle OpenWorld 2015.

EMC Rocks Oracle OpenWorld

EMC has a concurrent event at the Elan Event Center (directly across the street from Moscone West) during OpenWorld. This event is a great opportunity to come see the most unique and powerful solutions and products EMC has to offer to folks using Oracle Database. You can register for the event at (more...)

Copy Data Management for Oracle Database with EMC AppSync and XtremIO

This is a quick blog entry to invite readers to view this little demonstration video I created. The topic is Copy Data Management in an Oracle Database environment. We all know the pains involved with the number of database copies needed in today’s Oracle environment. Well, how about technology with these characteristics:

  1. 100% space efficient. There is no need for any full-copy “donor” in this solution. You can create 8192 XtremIO Virtual Copies of volumes (more...)

Focusing on Ext4 and XFS TRIM Operations – Part I.

I’ve been doing some testing that requires rather large file systems. I have an EMC XtremIO Dual X-Brick array from which I provision a 10 terabyte volume. Volumes in XtremIO are always thinly provisioned. The testing I’m doing required me to scrutinize default Linux mkfs(8) behavior for both Ext4 and XFS. This is part 1 in a short series and it is about Ext4.

Discard the Discard Option

The first thing I noticed in this (more...)

Announcing “SLOB Recipes”

I’ve started updating the SLOB Resources page with links to “recipes” for certain SLOB testing. The first installment is the recipe for loading 8TB scale SLOB 2.3 Multiple Schema Model with a 2-Socket Linux host attached to EMC XtremIO. Recipes will include (at a minimum) the relevant SLOB program output (e.g., or, init.ora and slob.conf.

Please keep an eye on the SLOB Resources page for updates…and (more...)

This Is Not Glossy Marketing But You Still Won’t Believe Your Eyes. EMC XtremIO 4.0 Snapshot Refresh For Agile Test / Dev Storage Provisioning in Oracle Database Environments.

This is just a quick blog post to direct readers to a YouTube video I recently created to help explain to someone how flexible EMC XtremIO Snapshots are. The power of this array capability is probably most appreciated in the realm of provisioning storage for Test and Development environments.

Although this is a silent motion picture I think it will speak volumes–or at least 1,000 words.

Please note: This is just a video demonstration to (more...)

Announcing SLOB 2.3. Tarry Not, Get It While It’s Hot!

This is just a quick post to announce SLOB 2.3. Please visit the SLOB Resources page to download the gzipped tar archive. The SLOB Resources page also has a link the SLOB 2.3 Documentation.

SLOB Resources Page: Click Here.

New in this release:

  1. The documentation is now also included in the tar archive under SLOB/doc in PDF form.
  2. SLOB 2.3 introduces the SLOB Single Schema feature. Please see the documentation.
  3. Because of (more...)

SLOB 2.3 User Guide

SLOB 2.3 is releasing within the next 48 hours. In case anyone wants to read about all the new features here is a link to the SLOB 2.3 User Guide:

SLOB 2.3 User Guide (pdf)


Filed under: oracle

SLOB 2.3 Is Getting Close!

SLOB 2.3 is soon to be released. This version has a lot of new, important features but also a significant amount of tuning in the data loading kit. Before sharing where the progress is on the front, I’ll quickly list some of the new important features that will be in SLOB 2.3:

  1. Single Schema Support. SLOB historically avoids application-level contention by having database sessions perform the SLOB workload against a private schema. The (more...)