From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: [PATCH 01/16 v5] pramfs: documentation Date: Mon, 3 Jan 2011 08:45:27 +0100 Message-ID: <20110103074526.GA2687@ucw.cz> References: <4D0A5377.1020007@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Linux Kernel , Linux Embedded , Linux FS Devel , Tim Bird , Andrew Morton To: Marco Stornelli Return-path: Content-Disposition: inline In-Reply-To: <4D0A5377.1020007@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org Hi! > +But the disk-based fs over non-volatile RAM block driver approach has > +some drawbacks: > + > +1. Complexity of disk-based fs: disk-based filesystems such as ext2/ext3/ext4 > + were designed for optimum performance on spinning disk media, so they > + implement features such as block groups, which attempts to group inode data > + into a contiguous set of data blocks to minimize disk seeking when accessing > + files. For RAM there is no such concern; a file's data blocks can be Yes, and they are also used on 99% of machines out there -> well debugged. Is there fsck for pramfs available, for example? > + This increases the efficient use of space on the media, i.e. more > + space is dedicated to actual file data storage and less to meta-data > + needed to maintain that file data. So... how big is overhead of pramfs compared to ext2? Can pramfs handle powerdown at arbitrary time? -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html