Constant Thinking | Technology Thoughts for the Quality Geek | by Constantin Gonzalez
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One of the first things to do when setting up a new system is to mirror your boot disk. This protects you against system disk failures: If one of the two mirrored boot disks fails, the system can continue running from the other disk without downtime. You can even boot from the surviving mirror half and continue using the system normally, until you have replaced the failed half.

At the currently low prices for boot drive sized disks, this is a no-brainer for increasing your system's availability, even for a home server system.

Unfortunately, the steps to complete until you're running off a mirrored ZFS root pool are not yet a no-brainer. While there is a piece of documentation entitled How to Configure a Mirrored Root Pool, it only covers how to add a second disk to your root pool, it does not cover how to prepare and layout a fresh disk so Solaris will accept it as a bootable second half of an rpool mirror.

Which, for historic reasons, is slightly more complicated than just saying zpool attach.

Over the weekend, I sat down and played a bit with the current Oracle Solaris 11 Express release in VirtualBox and tested, re-tested and investigated all currently necessary steps to get your root pool mirrored, including some common issues and variations.

Here's a complete, step-by-step guide with background information on how to mirror your ZFS root pool:

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A few weeks ago, a reader asked me a couple of questions about SSDs and ZFS, hinting that this might be a good topic to write a blog post about.

Sure enough, just last week, a couple of similar questions came up, this time from a customer and a colleague at work.

Well, if that's not a sign from heaven, I don't know what is, so here's a collection of frequently asked questions about flash memory (also known as solid state disks, or SSDs) and ZFS, with answers and some useful links, and an index, too.

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Screenshot from the video

About 4 years ago, a few colleagues and myself got together and we created a short video about the coolness of two of the most innovative products from Sun of the last decade: ZFS and the X4500 Server.

Today, nearly 4 years later, the video has been downloaded more than 100,000 times (across the original German and the English dubbed version, plus the full resolution downloadable files) and shown to a lot more people during tradeshows, customer demos, etc.

Now YouTube and Google Video (remember?) don't allow for highest video quality and the old Sun Mediacast server, where we hosted the original MP4 file, no longer exists. Instead, Vimeo has emerged as my video hoster of choice for a variety of projects (check out my video collection on Vimeo) and so it was time to give this video a new home.

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4 commands that help you find bottlenecks

A while ago, we discussed some performance analysis basics:

  • Define what your problem is.

  • Figure out your goal: What metric needs to be in what ballpark for you to declare victory?

  • Analyze your system from the inside out: CPU, RAM, Disk, Network. Your Bottleneck is always in one of these 4 regions.

So what are the best commands for finding bottlenecks in each of the four categories above? Here's part two of my Oracle Solaris Performance cheat sheet with some favorite tricks.

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A review of 2010 and plans for 2011

12.01.2011, updated: 03.10.2017

2011 is coming down the road

The year 2011 is almost two weeks old, and by now you've probably read every other review/resolutions/plans blog post out there. Now you have time to read this one :).

But first of all: Apologies for not having blogged for weeks. I've been moving to a new home over the last two months, the holiday season took its toll and there were a few other personal and job projects that demanded my attention.

Now, normality (whatever it is) is starting to come back and I can start devoting more time to this blog again.

This blog is now one year old, although I had been blogging for more than five years before. Time to reflect, plan and flip some switches for the future.

Here's a quick recap of 2010, some plans and ideas for this blog, a call for feedback and hints to some other projects for 2011.

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Monitis.jpg

Whenever you run a professional server, a home server, a hosted virtual server or just a blog on a shared web space, you run a service that provides something useful to your users, readers or whatever consumers your service caters to.

Too bad if things go wrong and you're the last to notice.

Enter Monitis.com*: This service allows you to easily track your servers, websites, blogs or anything else that can be accessed through the internet, or that is able to run a simple agent. Monitoring from the cloud, if you will, at reasonable prices. And if all you need is some basic monitoring, then there's a free version called mon.itor.us, too.

Let's check this out in some detail:

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solaris_11_express.jpg

At last, it is here: After lots of waiting, speculation, community self-help efforts, future directions, anticipation and more, we're now holding it in our hands: Oracle Solaris 11 Express is here!

While you're testing/installing/upgrading to this new release, let's check out the following top 7 cool things about Oracle Solaris 11 Express:

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sparc_t3.jpg

Before we continue our little Performance Analysis Series, let's look at some current news:

The Bad News: HTTP is dead. Get over it. The killer? It's called Firesheep, a free Firefox extension that makes it trivially easy for that kid sitting next to you in that Wifi hotspot to steal your Facebook, Twitter or other web services' identity.

The Victims: The first line of victims are of course millions of unsuspecting users that are sitting in WLAN areas, not knowing that their web identities can be stolen at the click of the button. But the real victims are hundreds, if not thousands of website owners, starting with the who-is-who of web companies, who are now (rightly so) faced with the challenge of upgrading their web infrastructure to HTTPS as soon as possible, preferably overnight.

The Good News: Adding encryption to your web servers used to be an additional burden on the CPU, negatively impacting performance by as much as 2-3x. Fortunately, the new SPARC T3 processors enable you to switch SSL encryption on for your web applications, without any performance impact. This is possible through built-in encryption engines at the core level. And thanks to the Oracle Solaris Cryptographic Framework, it's easy to take advantage of hardware encryption for any application that needs it.

Wanna learn more? Read on!

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Over time, you tend to learn a Solaris performance trick or two. Or three. Or more. That's cool, it's how stuff works: You learn, you do, you remember.

Performance analysis and tuning is just like that: You learn a trick from a person that is more senior than you are, you apply it, you feel like a hero, you learn the next trick.

But having a bag of tricks is not enough. Because then you start trying out stuff without a system, and spend useless time hunting that problem with a hit-and-miss approach, gut-based only.

Therefore, I'm always glad to listen to Ulrich Gräf when he does one of his famous performance tuning workshops (if you're lucky, you can catch Uli blogging in German here), because he'll give you the full view, the context and the system too, when it comes to performance analysis.

So here's my personal cheat sheet for Oracle Solaris Performance Analysis, including some guideance on how to systematically catch that elusive bottleneck.

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Book Review: The Art of Non-Conformity by Chris Guillebeau

A guy I know once said: "If you follow the herd, you'll end up as lunch." (Actually, he said "Schnitzel", since he's German, but you get the idea).

Well, here's a guide, a manual if you wish, for avoiding the fate of leading a dull, boring and unremarkable life. This is not just a self-help or success guide type of book, it's much more. It's a manifesto for personal freedom that can apply to all of us, if we choose to follow it.

In some ways, it's like the red pill/blue pill thing from The Matrix: Do you want to stay in the normal world, do normal, boring things like getting a job, applying for a mortgage, going on vacation once or twice a year, and feeding the ducks in the park after you retire?

Or do you want to decide for yourself what to do with your life, create your own rules and live your life the way you want?

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For my last article, I wanted to include a couple of videos from YouTube.

First, I pondered using the standard YouTube embed code, but I wanted a more simple, elegant solution. The Drupal RepTags module supports powerful macros and it comes with some pre-built YouTube macros, so that wasn't bad.

But I wanted more: HTML5. Read on and see how easily you can create your own Drupal RepTags, including the code I use to add HTML5 support for the Drupal YouTube RepTag.

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Oracle Solaris 10 09/10: ZFS Highlights

13.09.2010, updated: 03.10.2017

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The recently announced Oracle Solaris 10, 09/10 release introduced a number of significant upgrades to the ZFS file system.

Ironically, Solaris 10 now comes with a higher ZFS pool version (19, at least) than OpenSolaris 2009.06 (14).

So let's look at some of the key ZFS improvements that came in this update and figure out why they're so useful.

In this article, you'll learn more about LUN Expansion, Snapshot Holds, Triple Parity RAID-Z, Log Device Improvements, Pool Recovery, Splitting Mirrors and we'll discover a new scheduler class!

And as a bonus, we'll get to watch some videos that explain these features in further detail.

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Oracle Solaris 11 is the future of enterprise IT, that is now clear.

Still, we need to wait a year until it is officially released. What can we do now? Well, quite a lot, it turns out. Even if the preview version (due later this year) hasn't been relased yet, there are a lot of things you can do to prepare for the big OS upgrade.

Here's a list of 11 things you can do now to start enjoying the benefits of Solaris 11, get ahead of your system peers and be a part of the future of Solaris now!

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How To Add Pre-/Post-Scripts to IPS Packages

20.08.2010, updated: 03.10.2017

Package Scripting

My last post about Solaris 11 triggered an interesting discussion with UX-admin about IPS and the lack of pre-/post-scripts for installation/removal.

Assuming that Solaris 11 will be based on IPS just like OpenSolaris, it is certain that sysadmins will have to change a lot in how they create and manage packages, because IPS is fundamentally different from the good old System V packaging system.

So let's explore the lack of scripting hooks in IPS and see if we can find some ways of working around them:

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Oracle Solaris 11 is the Future

18.08.2010, updated: 03.10.2017

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Lots of speculation about Solaris and OpenSolaris is happening right now, with an allegedly leaked email being the latest generator of buzz, rumors and troll-ism.

But is that any useful? No.

So let's cut through the shiitake, do some due diligence and focus on some real facts instead.

In this article, we'll check out some real and authoritative sources of Solaris direction, mainly John Fowler's recent webcast about Solaris 11. Then we'll see what our future opportunities as members of the Solaris community are, and close with some pointers to other opinions on Solaris 11.

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Ever since Oracle announced that they'll buy Sun, there has been a lot of discussion about the future (some would say "fate") of OpenSolaris in the "community".

In fact, the last 15 months have been very instructive in terms of how communities work, or how they don't.

Let's check out what a community is supposed to do, and what it is not supposed to do, in the light of the latest OpenSolaris announcement: Illumos.

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Every year, on the last Friday of July, Sysadmin Day is celebrated around the world.

You know, the guy (or gal) that makes sure you always receive your emails on time, strips away the spam, cuddles your web server so you can write blog articles, or makes sure the network is always online, so you can read your favorite blogs. Or install new servers and storage so your web experience becomes faster and so your data is never lost.

Sysadmins often have a hard time: Noone calls them to tell them "Thank you for delivering all my emails!" or "Thanks for making sure my data is backed up every day!". Instead, they only get phonecalls when something goes wrong, or worse yet, some anonymous electronic complaint in some soulless ticketing system.

Therefore, this Friday, the 30th of July, 2010, think about your sysadmin, call her up and say something nice, or consider giving them a gift. Here are some geeky gift ideas for sysadmins to celebrate Sysadmin Day 2010, from low-budget to truely-devoted-appreciation pricing order.

After all, you really don't want your sysadmin to turn into a grumpy BOFH, do you?

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zil.jpg

When talking to customers, partners and colleagues about Oracle Solaris ZFS performance, one topic almost always seems to pop up: Synchronous writes and the ZIL.

In fact, most ZFS performance problems I see are related to synchronous writes, how they are handled by ZFS through the ZIL and how they impact IOPS load on the pool's disks.

Many people blame the ZIL for bad performance, and they even try to turn it off, but that's not good. Actually, the opposite is true: The ZIL is there to help you.

In this article, we'll learn what synchronous writes are, how they're processed by ZFS, what the ZIL is, how it works, how to measure ZIL activity and how to accelerate synchronous write performance, which is at the root of many, if not the majority of ZFS performance problems.

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The ProBlogger 7 Links Challenge #7links

15.07.2010, updated: 03.10.2017

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Darren from ProBlogger today posted his 7 Link Challenge. A fun idea in which he asks bloggers to share 7 links to posts, based on the 7 criteria he selected.

ProBlogger is a great website with lots of useful tips for bloggers. Even if you don't plan to make money with your blog, or if you don't think of yourself as a pro blogger, this site is still one of the best in terms of blogging advice.

I'm currently reading his book "ProBlogger" (affiliate link) and I can highly recommend it to anyone who is thinking more seriously about blogging.

Now, let's get started with the ProBlogger 7 Link Challenge for Constant Thinking:

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One of the best information sources for any topic are blogs, and the Oracle Solaris operating system in all its variants (Solaris 10 and OpenSolaris) is no exception. Most of what I learned about OpenSolaris was through blogs, or through interacting with Solaris bloggers.

As a way of saying "Thank You", I did some research and came up with a list of the top ten Solaris related blogs with the highest traffic on the Internet.

But first, let's clear up some basic rules.

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Welcome!

This is the blog of Constantin Gonzalez, a Solutions Architect at Amazon Web Services, with more than 25 years of IT experience.

The views expressed in this blog are my own and do not necessarily reflect the views of my current or previous employers.


Copyright © 2017 – Constantin Gonzalez – Some rights reserved.
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