From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from doorbell.lineo.com ([204.246.147.253] helo=thor.lineo.com) by pentafluge.infradead.org with esmtp (Exim 3.22 #1 (Red Hat Linux)) id 15tJAg-0006hq-00 for ; Tue, 16 Oct 2001 02:37:31 +0100 Message-ID: <3BCB8F35.61CC1A8B@Rikers.org> Date: Mon, 15 Oct 2001 19:36:53 -0600 From: Tim Riker MIME-Version: 1.0 To: Jose =?gb2312?B?Um9kcu1ndWV6?= Argente CC: linux-mtd@lists.infradead.org Subject: Re: Read Only FS References: <3BCAED35.3000309@tid.es> Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Sender: linux-mtd-admin@lists.infradead.org Errors-To: linux-mtd-admin@lists.infradead.org List-Help: List-Post: List-Subscribe: , List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: three main choices: romfs, cramfs, jffs2 romfs is uncompressed and so does not need to decompress. cramfs is compressed and indexed, and so has shorter boot time jffs2 is compressed but must do a full scan on bootup. It can be read/write. Consider that flash reads may actually take longer than decompression depending on your hardware. I'd recommend a single jffs2 partition for most applications. This is the best use of a small amount of flash. Mount it readonly most of the time if you like and have some way to snapshot the current config data that remounts read-write, saves, and then remounts read-only. I have often made /var ramfs with /tmp -> /var/tmp, and /dev -> /var/dev so that writes can happen there. Then the bootup script fully populate /var. Jose Rodr=EDguez Argente wrote: >=20 > Hello, >=20 > I am working on an Assabet platform. My application will have a > significant part of the root filesystem mounted as read-only. I am > thinking about installing it as romfs, which I think should be faster > than JFFS2. Am I right? >=20 > Another question is wether romfs runs over MTD or it has its own access > layer. >=20 > Thank you very much >=20 > =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F= =5F=5F=5F=5F=5F > Linux MTD discussion mailing list > http://lists.infradead.org/mailman/listinfo/linux-mtd/ --=20 Tim Riker - http://rikers.org/ - short SIGs! All I need to know I could have learned in Kindergarten ... if I'd just been paying attention.