From mboxrd@z Thu Jan 1 00:00:00 1970 From: RK Subject: Re: when/why to use diffferent raid values for btrfs data & metadata? Date: Sun, 24 Jan 2010 06:28:53 -0500 Message-ID: <4B5C2EF5.9010804@computer.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Cc: linux-btrfs@vger.kernel.org To: unlisted-recipients:; (no To-header on input) Return-path: In-Reply-To: List-ID: try this article "Linux Don't Need No Stinkin' ZFS: BTRFS Intro & Benchmarks" http://www.linux-mag.com/id/7308/3/ , there is a benchmark table and speed analysis (very informative), but all the benchmarks are done with same -m and -d mkfs.btrfs option mail ignored wrote: > Hi, > > Just getting started with btrfs. > > I understand that btrfs stores data/metadata in two different tree > structures =96 one for file/directory names, and one for data blocks. > > Reading @, > > http://btrfs.wiki.kernel.org/index.php/Using_Btrfs_with_Multiple_Dev= ices > Use raid10 for both data and metadata > mkfs.btrfs -m raid10 -d raid10 /dev/sdb /dev/sdc /dev/sdd /dev/sd= e > > and @, > > "Churning Butter(FS): An Interview with Chris Mason" > http://www.linux-mag.com/id/7329 > > CM Today you can do this: > mkfs.btrfs -m raid1 -d raid10 /dev/sda /dev/sdb /dev/sdc /dev/sdd > And you=92ll get metadata on raid1 and data on raid10. The raid10 wil= l > use all four drives and the raid1 will use two drives at a time. Yes, > btrfs allows you to pick different values for data or metadata. > > The fact that I *can* setup data & metadata differently is clear. Bu= t > I'm not at all clear *why* I'd want to, or what the advantages are. > I'd guess it's a balance/combination of performance & resiliency. > > Naively "-m raid10 -d raid10" seems to make the most sense -- if i > have it, use it. > > Are there any benchmarks, guidelines or recommendations? > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs= " in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > =20 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" = in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html