File System Performance on FreeBSD
Is there any justification for this benchmark? http://www.phoronix.com/scan.php?page=articleitem=zfs_ext4_btrfsnum=2 http://www.phoronix.com/scan.php?page=articleitem=zfs_ext4_btrfsnum=2 Regards, GB ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: File System Performance on FreeBSD
On 8/8/10 10:03:59 AM, Kiswono Prayogo wrote: Is there any justification for this benchmark? http://www.phoronix.com/scan.php?page=articleitem=zfs_ext4_btrfsnum=2 http://www.phoronix.com/scan.php?page=articleitem=zfs_ext4_btrfsnum=2 Kind of hard to do much with that benchmark First off: * Does the author even know what he's doing? All that article does is display the charts, then tell you what the chart says. The author shows no understanding of what's going on. * He's running the tests on a laptop. * He had a single disk/partition, which was the same disk/partition that he was running the OS off. The difference in speed might have been the result of different software being installed on the different OS that was competing for disk usage. * All of his tests involve tiny amounts of data and/or extremely quick run times (less than 30s). On a system with 4G of ram, the different caching policies on the different FS can have a huge difference on the results. While it's interesting to study those caching differences, it's not anywhere indicative of overall FS performance. Let him run one of those tests for 5 mins and see if the results are still the same. But, most importantly, his benchmarks are useless for any productive use. He doesn't describe the tests he's doing with enough detail for anyone else to attempt to reproduce them and attempt to address the problem. What does he mean by gzip test? Can I see the command line parameters involved? How many runs of each test did he do? What other programs were accessing the disk at the time? What other programs were _running_? There's nothing wrong with PC-BSD, but it installs a lot of stuff at install time -- there may be programs running that are hurting the results that aren't running on Ubuntu. Since that was a laptop, what is the powersave policy for the disks in each case? Did he do a single run of each test? That produces the most unreliable results ever. Overall, it's just sloppy reporting if you ask me. For all I know, he actually did a really good job of making sure that everything was set up to be fair, but the article doesn't say that. It's pretty typical of most reporting, not enough depth or care to be useful. I'm sure there are Linux people who will be shouting about this all over the place. But to the casual observer, all this tells you is that Linux's filesystems _may_ be faster for short, bursty work. To someone technical who might be looking to investigate the results with an eye toward fixing them, it's useless. -- Bill Moran ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: File System Performance on FreeBSD
On Sun, 08 Aug 2010 13:13:46 -0400 Bill Moran wmo...@potentialtech.com wrote: To someone technical who might be looking to investigate the results with an eye toward fixing them, it's useless. Anyone can download the Phoronix Test Suite though, so it should be fairly easy to check if the results are valid at least. -- Bruce Cran ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: File System Performance on FreeBSD
On Sun, Aug 8, 2010 at 12:13 PM, Bill Moran wmo...@potentialtech.comwrote: On 8/8/10 10:03:59 AM, Kiswono Prayogo wrote: Is there any justification for this benchmark? http://www.phoronix.com/scan.php?page=articleitem=zfs_ext4_btrfsnum=2 http://www.phoronix.com/scan.php?page=articleitem=zfs_ext4_btrfsnum=2 I'm sure there are Linux people who will be shouting about this all over the place. But to the casual observer, all this tells you is that Linux's filesystems _may_ be faster for short, bursty work. Here's a more detailed explanation. http://lists.freebsd.org/pipermail/freebsd-hackers/2010-June/032031.html -- Adam Vande More ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: File System Performance on FreeBSD
Hi, I heard that Linux filesystems were not reliable because of some bad way of doing caching or something like that. For a study on Linux FS reliability see [1] by Toshiba guys. It seems Linux was upset on this about one year ago [2]. Quoting: Torvalds, for one, didn't seem too excited about the delayed synchronization. He writes on the mailing list, Doesn't at least ext4 default to the insane model of 'data is less important than metadata, and it doesn't get journalled'? And ext3 with 'data=writeback' does the same, no? Both of which are -- as far as I can tell -- total brain damage. I don't mind if a filesystem is very fast: I want it to be reliable first. I wonder if that Phoronix test suite checks for reliability first or not. Cheers, Antonio [1] elinux.org/images/2/26/Evaluation_of_Data_Reliability-ELC2010.pdf [2] http://www.linux-magazine.com/Online/News/Linus-Torvalds-Upset-over-Ext3-and-Ext4 On 08/08/2010 19:22, Bruce Cran wrote: On Sun, 08 Aug 2010 13:13:46 -0400 Bill Moranwmo...@potentialtech.com wrote: To someone technical who might be looking to investigate the results with an eye toward fixing them, it's useless. Anyone can download the Phoronix Test Suite though, so it should be fairly easy to check if the results are valid at least. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: File System Performance on FreeBSD
On Sunday 08 August 2010 20:55:40 Antonio Vieiro wrote: I don't mind if a filesystem is very fast: I want it to be reliable first. I wonder if that Phoronix test suite checks for reliability first or not. https://ext4.wiki.kernel.org/index.php/Ext4_Howto#Barriers_on_by_default Since it has been declared stable, the performance of ext4 has dropped due to various reliability fixes, culminating with the making of write barriers a default. More info here: http://lwn.net/Articles/283161/ -- Mihai Donțu ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
