Looking forward: 2016

We’re already over one week in 2016 and I realize I haven’t done much blogging lately.

One of the things that kept me busy is development on Outrun, and the joint Oracle / EMC Solution Center (OSC) on which I intend to write a bit more going forward.

Something I did about a year ago (without mentioning it too much) is upgrade my WordPress.com account to Professional. Not that I really need the extra add-ons, but I want my readers not to be disturbed by ads – OK, there’s ad blockers, but not everyone uses them, and on some platforms you simply can’t (iOS). Dirty Cash well spent (and no, I don’t get it reimbursed by my employer if you’d think that, my blog is mine, mine only and independent).

adblockwelcomeGiven that the number of page views on Dirty Cache passed a quarter million last year (thanks to all my readers), can you imagine the savings in bandwidth and productivity loss by not showing ads? ;-)

So what else can you expect from me this year?

Of course, more about running Oracle on EMC and why I think that’s a pretty good idea. As the competition with Oracle is heating up, I intend to write more on comparing the differences between the solutions of both companies, debunking some marketing and competitive claims, and more. I also hope to find time to maintain the wiki on the Outrun site, and in addition to Outrun documentation, it might be a good place to put Oracle / EMC related howto’s, best practices, FAQs and more.

You also might be wondering what’s going to happen around Oracle / EMC solutions during the Dell / EMC aquisition… Me too. But we can’t (and are not allowed to) comment on it until the merger is final. Until then, business as usual. When the time is ready I’ll comment on new Dell / EMC / Oracle stuff where possible.

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Interview with Madora

A while ago I was interviewed by Kay Williams of Madora Consulting.

Madora Interview

As many customers are overwhelmed by licensing, audit and compliancy issues, I highly recommend my EMEA readers to reach out to Madora if you need independent assistance in that area.

In the interview we discussed a bit of my background, the challenges my customers are facing and how we help them, a bit on the future of Oracle and EMC as well as things like Cloud computing, how EMC sometimes competes with Oracle, my views on Oracle Engineered Systems, and where the two companies are fundamentally different. It has been out there for a while but I was enjoying vacation so I haven’t mentioned it before, but here it is :-)

Expected reading time about 10 minutes. Many thanks to Kay for the interview!

Enjoy: Madora – Interview with Bart Sjerps of EMC

This post first appeared on Dirty Cache by Bart Sjerps. Copyright © 2011 – 2015. All rights reserved. Not to be reproduced for commercial purposes without written permission.

Fun with Linux UDEV and ASM: Using UDEV to create ASM disk volumes

floppy-disksBecause of the many discussions and confusion around the topic of partitioning, disk alignment and it’s brother issue, ASM disk management, hereby an explanation on how to use UDEV, and as an extra, I present a tool that manages some of this stuff for you.

The questions could be summarized as follows:

  • When do we have issues with disk alignment and why?
  • What methods are available to set alignment correctly and to verify?
  • Should we use ASMlib or are there alternatives? If so, which ones and how to manage those?

I’ve written 2 blogposts on the matter of alignment so I am not going to repeat myself on the details. The only thing you need to remember is that classic “MS-DOS” disk partitioning, by default, starts the first partition on the disk at the wrong offset (wrong in terms of optimal performance). The old partitioning scheme was invented when physical spinning rust was formatted with 63 sectors of 512 bytes per disk track each. Because you need some header information for boot block and partition table, the smart guys back then thought it was a good idea to start the first block of the first data partition on track 1 (instead of track 0). These days we have completely different physical disk geometries (and sometimes even different sector sizes, another interesting topic) but we still have the legacy of the old days.

If you’re not using an Intel X86_64 based operating system then chances are you have no alignment issues at all (the only exception I know is Solaris if you use “fdisk”, similar problem). If you use newer partition methods (GPT) then the issue is gone (but many BIOSes, boot methods and other tools cannot handle GPT). As MSDOS partitioning is limited to 2 TiB (http://en.wikipedia.org/wiki/Master_boot_record) it will probably be a thing of the past in a few years but for now we have to deal with it.

Wrong alignment causes some reads and writes to be broken in 2 pieces causing extra IOPS. I don’t have hard numbers but a long time ago I was told it could be an overhead of up to 20%. So we need to get rid of it.

ASM storage configuration

ASM does not use OS file systems or volume managers but has its own way of managing volumes and files. It “eats” block devices and these block devices need to be read/write for the user/group that runs the ASM instance, as well as the user/group that runs Oracle database processes (a public secret is that ASM is out-of-band and databases write directly to ASM data chunks). ASM does not care what the name or device numbers are of a block device, neither does it care whether it is a full disk, a partition, or some other type of device as long as it behaves as a block device under Linux (and probably other UNIX flavors). It does not need partition tables at all but writes its own disk signatures to the volumes it gets.

[ Warning: Lengthy technical content, Rated T, parental advisory required ]

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Getting the Best Oracle performance on XtremIO

(Blog repost from Virtual Storage Zone – Thanks to @cincystorage)

UPDATE: I’ll say it again because there seems to be some confusion: THIS IS A REPOST!

Original content is from the Virtual Storage Zone blog (not mine). Just reposted here because it’s interesting and related to Oracle, performance and EMC storage. Enjoy…

XtremIO is EMC’s all-flash scale out storage array designed to delivery the full performance of flash. The array is designed for 4k random I/O, low latency, inline data reduction, and even distribution of data blocks.  This even distribution of data blocks leads to maximum performance and minimal flash wear.  You can find all sorts of information on the architecture of the array, but I haven’t seen much talking about archive maximum performance from an Oracle database on XtremIO.

The nature of XtremIO ensures that’s any Oracle workload (OLTP, DSS, or Hybrid) will have high performance and low latency, however we can maximize performance with some configuration options.  Most of what I’ll be talking about is around RAC and ASM on Redhat Linux 6.x in a Fiber Channel Storage Area Network.

Read the full blogpost here.


TheCube interview EMC World 2014

Being interviewed yesterday at EMC World 2014 by Wikibon and SiliconAngle.


Bart @ The Cube

Update: You can find a report of the interview here: Best Practices for Putting Your Oracle Database into the Cloud

Linux Disk Alignment Reloaded

railtrackmisalignMy all-time high post with the most pageviews is the one on Linux disk alignment: How to set disk alignment in Linux. In that post I showed an easy method on how to set and check disk alignment under linux.
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ZFS and Database fragmentation

Disk Fragmentation

Disk Fragmentation – O&O technologies.
Hope they don’t mind the free advertising

Yet another customer was asking me for advice on implementing the ZFS file system on EMC storage systems. Recently I did some hands-on testing with ZFS as Oracle database file store so that I could get an opinion on the matter.

One of the frequent discussions comes up is on the fragmentation issue. ZFS uses a copy-on-write allocation mechanism which basically means, every time you write to a block on disk (whether this is a newly allocated block, or, very important, overwriting a previously allocated one) ZFS will buffer the data and write it out on a completely new location on disk. In other words, it will never overwrite data in place. Now a lot of discussions can be found in the blogosphere and on forums debating whether this is really the case, how serious this is, what the impact is on performance and what ZFS has done to either prevent, or, alternatively, to mitigate the issue (i.e. by using caching, smart disk allocation algorithms, etc).

In this post I attempt to prove how database files on ZFS file systems get fragmented on disk quickly. I will not make any comments on how this affects performance (I’ll save that for a future post). I also deliberately ignore ZFS caching and other optimizing features – the only thing I want to show right now is how much fragmentation is caused on physical disk by using ZFS for Oracle data files. Note that this is a deep technical and lengthy article so you might want to skip all the details and jump right to the conclusion at the bottom :-)

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Big Ideas; Big Tech: Continuous Operations for Oracle RAC with EMC VPLEX

Here’s an EMC video on Youtube about Oracle RAC with EMC VPLEX. Very nice, check it out!




Looking back and forward

I have been enjoying a short holiday in which I decided to totally disconnect from work for a while and re-charge my battery. So while many bloggers and authors in our industry were making predictions for 2013, I was doing some other stuff and blogging was not part of that ;-)

Now that we survived the end of times let’s look back and forward a bit. I don’t want to burn myself making crazy predictions about this year but still like to present some thoughts for the longer term. Stay tuned…

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VMware is really expensive

costcalcA while ago somebody forwarded me a research paper from an “independent” research firm in which the cost of VMware and Oracle VM were compared. Interesting!

Now you might wonder why, as someone working for EMC, I would care about such comparisons. Why would I be bothered by VMware in the first place?

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