From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc MERLIN Subject: brtfs on top of dmcrypt with SSD. No corruption iff write cache off? Date: Sun, 29 Jan 2012 16:37:54 -0800 Message-ID: <20120130003754.GD4380@merlins.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: linux-btrfs@vger.kernel.org Return-path: List-ID: Howdy, I'm considering using brtfs for my new laptop install. Encryption is however a requirement, and ecryptfs doesn't quite cut it for me, so that leaves me with dmcrypt which is what I've been using with ext3/ext4 for years. https://btrfs.wiki.kernel.org/articles/g/o/t/Gotchas.html still states that 'dm-crypt block devices require write-caching to be turned off on the underlying HDD' While the report was for 2.6.33, I'll assume it's still true. I was considering migrating to a recent 256GB SSD and 3.2.x kernel. First, I'd like to check if the 'turn off write cache' comment is still accurate and if it does apply to SSDs too. Second, I was wondering if anyone is running btrfs over dmcrypt on an SSD and what the performance is like with write cache turned off (I'm actually not too sure what the impact is for SSDs considering that writing to flash can actually be slower than writing to a hard drive). Thanks, Marc -- "A mouse is a device used to point at the xterm you want to type in" - A.S.R. Microsoft is to operating systems .... .... what McDonalds is to gourmet cooking Home page: http://marc.merlins.org/