ZFS - Building, Testing, and Benchmarking
by Matt Breitbach on October 5, 2010 4:33 PM EST- Posted in
- IT Computing
- Linux
- NAS
- Nexenta
- ZFS
Demise of OpenSolaris?
You may have heard some troubling news about the fate of OpenSolaris recently. Based on some of the rumors floating around, you might think OpenSolaris is going away, never to be seen again. Admittedly, OpenSolaris has never been an open source project in quite the same way that Linux has. Sun launched the OpenSolaris project to help promote its commercialware Solaris product. Sun seemed to do a decent job of managing the OpenSolaris project, but Sun is no longer in charge. The project is now at the mercy of Oracle.
The OpenSolaris Governing Body (OGB) has struggled to get Oracle to continue to work with the OpenSolaris project. Oracle’s silent treatment has gotten so bad that the OGB threatened to dissolve itself and return control of the OpenSolaris community to Oracle on August 23 if Oracle did not appoint a liaison to the community by August 16, 2010. It is pretty safe to assume that Oracle, clearly a for profit company, would benefit more from allowing the OGB to dissolve. That would give Oracle the option to do what ever they wanted with OpenSolaris, including simply killing the project.
At this point, two possible outcomes seem the most likely. One possible outcome is that Oracle will continue to offer OpenSolaris but will tighten its grip over the direction of the project. Perhaps Oracle would use the opportunity to make some technical changes within OpenSolaris to limit the scope of the product so as not to compete directly with commercialware offerings.
The other outcome is that a fork will occur in the project, possibly resulting in several different projects. Regardless of Oracle, OpenSolaris appears to be living on through the Illumos project located at http://www.illumos.org/ - There hasn't been much activity yet in the Illumos project, but it's only been announced for a few weeks. We will be closely monitoring this to see if it will be a suitable replacement for OpenSolaris. Illumos was initiated by Nexenta employees in collaboration with OpenSolaris community members and volunteers. While Nexenta does sponsor some of the work, Illumos is independent of Nexenta. Illumos aims to be a common base for multiple community distributions. It is run by the community on a system of meritocracy. Distributions like Nexenta, Belenix and Schillix will move to using Illumos as the base for their distributions, and other distributions have shown interest as well.
Personally, I don’t think the situation is as dire as some people suggest. Oracle now owns MySQL as well as OpenSolaris, yet millions of us continue to use these products. If Oracle does over exert control to the point that it chokes off these open source products, then we can always resort to forking the code and getting behind the new open source projects.
As far as using OpenSolaris, I don’t see Oracle’s ownership as a reason to give up on using OpenSolaris. If you are considering deploying a ZFS based
A final note on the possible demise of OpenSolaris is that OpenSolaris may now be officially dead. According to an internal Oracle announcement that was posted into some mailing lists, Oracle is killing off OpenSolaris and replacing it with Solaris 11 Express. Additionally, Oracle claims they will continue to release open source snapshots of Solaris after each major release instead of releasing nightly builds, but that does not sound like a typical open source project.
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MGSsancho - Tuesday, October 5, 2010 - link
I haven't tried this myself yet but how about using 8kb blocks and using jumbo frames on your network? possibly lower through padding to fill the 9mb packet in exchange for lower latency? I have no idea as this is just a theory. dudes in the #opensolaris irc chan have always recommended 128K or 64K depending on the data.solori - Wednesday, October 20, 2010 - link
One easy way to check this would be to export the pool from OpenSolaris and directly import it to NexentaStor and re-test. I think you'll find that the differences - as your benchmarks describe - are more linked to write caching at the disk level than partition alignment.NexentaStor is focused on data integrity, and tunes for that very conservatively. Since SATA disks are used in your system, NexentaStor will typically disable disk write cache (write hit) and OpenSolaris may typically disable device cache flush operations (write benefit). These two feature differences can provide the benchmark differences you're seeing.
Also, some "workstation" tuning includes the disabling of ZIL (performance benefit). This is possible - but not recommended - in NexentaStor but has the side effect of risking application data integrity. Disabling the ZIL (in the absence of SLOG) will result in synchronous writes being committed only with transaction group commits - similar performance to having a very fast SLOG (lots of ARC space helpful too).
fmatthew5876 - Tuesday, October 5, 2010 - link
I'd be very interested to see how FreeBSD ZFS benchmark results would compare to Nexenta and Open Solaris.mbreitba - Tuesday, October 5, 2010 - link
We have benchmarked FreeNAS's implimentation of ZFS on the same hardware, and the performance was abysmal. We've considered looking into the latest releases of FreeBSD but have not completed any of that testing yet.jms703 - Tuesday, October 5, 2010 - link
Have you benchmarked FreeBSD 8.1? There were a huge number of performance fixes in 8.1.Also, when was this article written? OpenSolaris was killed by Sun on August 13th, 2010.
mbreitba - Tuesday, October 5, 2010 - link
There was a lot of work on this article just prior to the official announcement. The development of the Illumos foundation and subsequent OpenIndiana has been so rapidly paced that we wanted to get this article out the door before diving in to OpenIndiana and any other OpenSolaris derivatives. We will probably add more content talking about the demise of OpenSolaris and the Open Source alternatives that have started popping up at a later date.MGSsancho - Tuesday, October 5, 2010 - link
Not to mention that projects like illumos are currently not recommended for production, Currently only meant as a base for other distros (OpenIndiana.) Then there is Solaris 11 due soon. I'll try out the express version when its released.cdillon - Tuesday, October 5, 2010 - link
FreeNAS 0.7.x is still using FreeBSD 7.x, and the ZFS code is a bit dated. FreeBSD 8.x has newer ZFS code (v15). Hopefully very soon FreeBSD 9.x will have the latest ZFS code (v24).piroroadkill - Tuesday, October 5, 2010 - link
This is relevant to my interests, and I've been toying with the idea of setting up a ZFS based server for a while.It's nice to see the features it can use when you have the hardware for it.
cgaspar - Tuesday, October 5, 2010 - link
You say that all writes go to a log in ZFS. That's just not true. Only synchronous writes below a certain size go into the log (either built into the pool, or a dedicated log device). All writes are held in memory in a transaction group, and that transaction group is written to the main pool at least every 10 seconds by default (in OpenSolaris - it used to be 30 seconds, and still is in Solaris 10 U9). That's tunable, and commits will happen more frequently if required, based on available ARC and data churn rate. Note that _all_ writes go into the transaction group - the log is only ever used if the box crashes after a synchronous write and before the txg commits.Now for the caution - you have chosen SSDs for your SLOG that don't have a backup power source for their on board caches. If you suffer power loss, you may lose data. Several SLC SSDs have recently been released that have a supercapacitor or other power source sufficient to write cache data to flash on power loss, but the current Intel like up doesn't have it. I believe the next generation Intel SSDs will.