Posts tagged "zfs"

Ever since I’ve been using a Mac, I enjoy using Sparse Encrypted Disk Images for a variety of tasks, for instance securely storing data that can be backed up somewhere else, say on a hosting server.

In fact, most of my project/personal data on my Mac sits on sparse encrypted disk images that are regularly rsynced to an external storage service, Strato’s in particular.

The beauty of this solution lies in it simplicity:

Sparse encrypted disk images show up just like any other hard drive. But on the back end, they translate into a bunch of flat files that store all the data in an encrypted manner. By rsyncing the backing store, sparse encrypted disk images can be easily backed up across the net, while ensuring privacy and convenience.

Here’s how to do similar things with Solaris and ZFS, including some extra data integrity magic:

In about a week, on November 9th, 2011, the long-awaited final version of Solaris 11 will be launched. If you happen to be near New York that day (and assuming there’ll be no power outages), you’re invited to join the official Solaris 11 launch party!

Solaris 11 has been in the making since 2005, when Solaris 10 was launched. In fact, every major Solaris release is just a fork of the ongoing Solaris development train, so the very first uber-pre-release of Solaris 11 was actually generated only weeks after Solaris 10 hit the shelves.

Since then, Solaris 11 (or: Project Nevada as it was called) has seen a lot of OS history: An open source adolescence called OpenSolaris, growing adoption and community work, a broad range of ground-braking new features, long overdue re-writes, brand new concepts, controversial discussions, a major acquisition, rules changed and rules kept, siblings and offsprings, lots of investments, entire companies built on top of its source code, generations of processors and hardware, lots of systems in production, the Cloud and what not.

And all that before it was even born. Quite an achievment, eh?

…that is the question.

Ever since the introduction of deduplication into ZFS, users have been divided into two camps: One side enthusiastically adopted deduplication as a way to save storage space, while the other remained skeptical, pointing out that dedupe has a cost, and that it may not be always the best option.

Let’s look a little deeper into the benefits of ZFS deduplication as well as the cost, because ultimately it boils down to running a cost/benefit analysis of ZFS deduplication. It’s that simple.

More than a while ago, I wrote about the birth of Illumos, a project that aims at substituting the last non-open-source bits from the OpenSolaris kernel with replacements, in order to create a 100% open source Solaris kernel.

On May 20th, I had the opportunity to attend the Nexenta European User Conference 2011 (no link, page no longer exists) in Amsterdam, where Solaris and storage enthusiasts from all over the world met to discuss their favorite technology: ZFS. Of course there was also a lot of talk about Illumos and related projects.

Now I’ve given a lot of Solaris presentations to customers, always highlighting the big, growing and powerful community behind the Solaris OS. But this conference added a new dimension to the Solaris Eco-System for me!

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 (no link, page no longer exists) 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:

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.

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.

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 (no link, page no longer exists)!

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:

The recently announced Oracle Solaris 10, 09/10 release (no link, page no longer exists) introduced a number of significant upgrades to the ZFS file system.

Ironically, Solaris 10 now comes with a higher ZFS pool version (19 (no link, opensolaris.org no longer exists), at least) than OpenSolaris 2009.06 (14 (no link, opensolaris.org no longer exists)).

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.

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 (no link, solarisinternals.com no longer exists), 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.

The developers of ZFS are a funny bunch of people. You can tell that by watching the “ZFS: The Next Word” talk, meeting them on conferences, reading their blogs or their comments on mailing lists.

And there are also some funny parts in the ZFS source code, too. In fact, if you use ZFS, you’ll have a funny joke sitting on your disk, right under your nose!

I was reminded about this particular joke while listening to Ulrich Gräf’s excellent talk on ZFS internal data structures during OSDevCon 2009 (no link, osdevcon.org no longer exists) (watch a video of Ulrich’s talk here (no link, sun.com no longer exists)).

But first, we need to dig a little bit into the world of ZFS data structures.

When looking at the mails and comments I get about my ZFS optimization and my RAID-Greed posts, the same type of questions tend to pop up over and over again. Here’s an example from a reader email: “I was reading about ZFS on your blog and you mention that if I do a 6 drive array for example, and a single RAID-Z the speed of the slowest drive is the maximum I will be able to achieve, now I thought that ZFS would be better in terms of speed. Please let me know if there is a newer ZFS version that improved this or if it does not apply anymore.” This is just an example, but the basic theme is the same for much for the reactions I see: Many people think that RAID-Z will give them always good performance and are surprised that it doesn’t, thinking it’s a software, an OpenSolaris or a ZFS issue.

In reality, it’s just pure logic and physics, and to understand that we should look a little closer at what vdevs are in ZFS and how they work.

This is a long article, but I hope you’ll still find it interesting to read. Let me know if you want me to break down future long articles into multiple parts instead.

One of the most frequently asked questions around ZFS is: “How can I improve ZFS performance?”.

This is not to say that ZFS performance would be bad. ZFS can be a very fast file system. ZFS is mostly self-tuning and the inherent nature of the algorithms behind ZFS help you reach better performance than most RAID-controllers and RAID-boxes - but without the expensive “controller” part.

Most of the ZFS performance problems that I see are rooted in incorrect assumptions about the hardware, or just unrealistic expectations of the laws of physics.

So let’s look at ten ways to easily improve ZFS performance that everyone can implement without being a ZFS expert.

During OSDevCon 2009 in Dresden (no link, osdevcon.org no longer exists), I had the honor to present on some lessons learned while putting together a ZFS Automatic-Scrubbing SMF service.

Today, Deirdre was so kind to publish the video recording of my presentation on The Oracle Solaris Video Blog (no link, sun.com no longer exists).

From the description:

This talk walks you through the implementation of a simple SMF service. What sounds "simple" at first, develops a life of its own when you consider installation/de-installation, security considerations, error handling and debugging, and of course unexpected little bugs and shortcomings. Finally, we add a GUI to our service by discovering the OpenSolaris Visual Panels project. This "lessons learned" talk is intended to be a practical roundup of things to consider for developers interested in integrating with SMF.

When I blogged about my OpenSolaris Home Server a while ago (no link, sun.com no longer exists), little did I know that this would become my most popular entry in my old blog!

In fact, R.G. (no link, page no longer exists) was so kind to call my setup “perilously close to being an AMD reference design (no link, opensolaris.org no longer exists)”. Thanks, R.G.! Read about his final setup here (no link, opensolaris.org no longer exists). And BTW, if you’re into e-guitars, check out his GEOFEX page, a great resource for guitar effects.

So let’s review our reference design and discuss some modifications to better suit your needs:

Since November 1st, 2009, when ZFS Deduplication was integrated into OpenSolaris (no link, genunix.org no longer exists), a lot has happened: We learned how it worked, people got to play with it, used it in production and it became part of the Oracle Sun Storage 7000 Unified Storage System (no link, sun.com no longer exists).

Here’s everything you need to know about ZFS Deduplication and a few links to help you dig deeper into the subject:

A lot of people have read last year’s article “A Small and Energy-Efficient OpenSolaris Home Server” (Thanks a lot to Andre Lue from the EON project for linking to it!) and there was quite some discussion on different RAID options as a result of my RAID-Greed article.

So let’s continue the theme and have a look at the following home server tips that helped me a lot during my own home server planning, building and installing:

After moving my blog to its new home and getting my hands dirty with Drupal, it’s time to continue my series of blog articles about setting up a home server. Remember? We talked about home server requirements (no link, sun.com no longer exists), then I presented to you my small and energy-efficient, still ECC-protected and powerful AMD-based home server (no link, sun.com no longer exists). Now it’s time to explore some different ZFS disk pool RAID strategies.