Comments on: Whither ZFS results? http://insidehpc.com/2008/07/08/whither-zfs-results/ HPC News Without the Noise for Supercomputing Professionals | insideHPC Sun, 19 May 2013 10:46:54 +0000 hourly 1 http://wordpress.org/?v=3.1.1 By: thinking sysadmin » Blog Archive » Catch-up Links, 7/9/2008 http://insidehpc.com/2008/07/08/whither-zfs-results/#comment-71609 thinking sysadmin » Blog Archive » Catch-up Links, 7/9/2008 Thu, 10 Jul 2008 18:47:19 +0000 http://insidehpc.com/2008/07/08/whither-zfs-results/#comment-71609 [...] zfs un-benchmarking - “Our rationale for testing was to finally get some numbers that we can provide to users/customers about real zfs performance. There is a huge amount of (largely uncontested) information (emanating mainly from Sun and its agents) that zfs is a very fast file system. We want to test this, on real, live hardware, and report. Well, we can’t do the latter due to Sun’s licensing, but we did do the former. Paraphrasing Mark Twain: ‘Rumors of zfs’s performance have been greatly exaggerated.’” When Joe Landman blogs about performance, I take what he has to say seriously, but given the stability problems he notes, I wonder if - as he suggests - that driver issues are a factor here, and we’re not seeing a generic ZFS issue. (Seen at InsideHPC.) [...] [...] zfs un-benchmarking – “Our rationale for testing was to finally get some numbers that we can provide to users/customers about real zfs performance. There is a huge amount of (largely uncontested) information (emanating mainly from Sun and its agents) that zfs is a very fast file system. We want to test this, on real, live hardware, and report. Well, we can’t do the latter due to Sun’s licensing, but we did do the former. Paraphrasing Mark Twain: ‘Rumors of zfs’s performance have been greatly exaggerated.’” When Joe Landman blogs about performance, I take what he has to say seriously, but given the stability problems he notes, I wonder if – as he suggests – that driver issues are a factor here, and we’re not seeing a generic ZFS issue. (Seen at InsideHPC.) [...]

]]> By: Joe http://insidehpc.com/2008/07/08/whither-zfs-results/#comment-71107 Joe Wed, 09 Jul 2008 02:41:18 +0000 http://insidehpc.com/2008/07/08/whither-zfs-results/#comment-71107 John As I have learned, Sun doesn't have this requirement on the OpenSolaris bits. So we can test performance with this. Discussions on and offline with others suggest that we will get better performance, and likely more help with that than with the Solaris version. Zfs is a very interesting file system. It is probably the easiest raid setup I have done to date. But the mdadm + mkfs isn't that far off, and could be wrapped in a script to make it just as simple to use. The interesting aspects of zfs are the checksumming, the error detection, and a few other capabilities. This is not something that an mdadm+mkfs script can replicate as easily. zfs is quite (badly) overhyped, but if you can work your way past this, there are real, and interesting elements there that are worth taking a look at. The issue I wanted to handle was how to tune our hardware for best zfs performance, for a customer who wanted to run the Sun official version. What annoyed me is that I cannot post the results of the tests, so we cannot compare these to other tests on (literally) this hardware. Unfortunately, due to its license (and the patents) zfs will not likely ever find its way into the Linux kernel. A shame, but things like <a href="http://btrfs.wiki.kernel.org/index.php/Main_Page" rel="nofollow">btrfs</a> are GPL, and will likely take its place (and given the GPL heritage, be available for many more OSes). Also <a href="http://ceph.newdream.net/" rel="nofollow">ceph</a>, and <a href="http://www.gluster.org/docs/index.php/GlusterFS" rel="nofollow">GlusterFS</a> are very interesting technologies in varying stages of completeness. GlusterFS in particular is robust enough for usage (and we have customers using it). Again, I hope we can get zfs performing well, and we would certainly like to see the Linux community using it. The <a href="http://zfs-on-fuse.blogspot.com/" rel="nofollow">Zfs on fuse</a> project is out there, but I am not sure how active it is right now. I see commits from a few months ago in the repository. Hopefully more people can contribute to this effort. John

As I have learned, Sun doesn’t have this requirement on the OpenSolaris bits. So we can test performance with this. Discussions on and offline with others suggest that we will get better performance, and likely more help with that than with the Solaris version.

Zfs is a very interesting file system. It is probably the easiest raid setup I have done to date. But the mdadm + mkfs isn’t that far off, and could be wrapped in a script to make it just as simple to use. The interesting aspects of zfs are the checksumming, the error detection, and a few other capabilities. This is not something that an mdadm+mkfs script can replicate as easily. zfs is quite (badly) overhyped, but if you can work your way past this, there are real, and interesting elements there that are worth taking a look at.

The issue I wanted to handle was how to tune our hardware for best zfs performance, for a customer who wanted to run the Sun official version. What annoyed me is that I cannot post the results of the tests, so we cannot compare these to other tests on (literally) this hardware.

Unfortunately, due to its license (and the patents) zfs will not likely ever find its way into the Linux kernel. A shame, but things like btrfs are GPL, and will likely take its place (and given the GPL heritage, be available for many more OSes). Also ceph, and GlusterFS are very interesting technologies in varying stages of completeness. GlusterFS in particular is robust enough for usage (and we have customers using it).

Again, I hope we can get zfs performing well, and we would certainly like to see the Linux community using it. The Zfs on fuse project is out there, but I am not sure how active it is right now. I see commits from a few months ago in the repository. Hopefully more people can contribute to this effort.

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