From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.pbcl.net ([88.198.119.4] helo=hetzner.pbcl.net) by linuxtogo.org with esmtp (Exim 4.72) (envelope-from ) id 1U2QNx-0003Tp-6Q for openembedded-core@lists.openembedded.org; Mon, 04 Feb 2013 19:03:22 +0100 Received: from cpc14-cmbg17-2-0-cust423.5-4.cable.virginmedia.com ([86.14.229.168] helo=[172.30.1.45]) by hetzner.pbcl.net with esmtpsa (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.72) (envelope-from ) id 1U2Q8f-0001HW-R2; Mon, 04 Feb 2013 18:47:29 +0100 Message-ID: <1360000031.6972.39.camel@phil-desktop.brightsign> From: Phil Blundell To: Laurentiu Palcu Date: Mon, 04 Feb 2013 17:47:11 +0000 In-Reply-To: <510F875B.9070903@intel.com> References: <510F8388.2030809@topic.nl> <510F875B.9070903@intel.com> X-Mailer: Evolution 3.4.4-1 Mime-Version: 1.0 Cc: openembedded-core@lists.openembedded.org Subject: Re: [PATCH 0/5] Remove /var/cache from volatiles directory X-BeenThere: openembedded-core@lists.openembedded.org X-Mailman-Version: 2.1.11 Precedence: list List-Id: Patches and discussions about the oe-core layer List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 04 Feb 2013 18:03:23 -0000 X-List-Received-Date: Mon, 04 Feb 2013 18:03:23 -0000 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit On Mon, 2013-02-04 at 12:03 +0200, Laurentiu Palcu wrote: > Not necessarily. We are trying to have all postinstalls run on host, so > we don't have to do any postinstall activity on target. Any cache > generated during postinstall, will be generated at do_rootfs time. Then, > we can deploy the image with the cache already in place. > > Also, on a RO rootfs, there is really no need to update the cache since > the cached files do not really change. Hence, the cache created on host > should, in theory, be valid. What sort of files in /var/cache are you trying to address with this change? The impression I have is that most of the things in there are created dynamically by applications running on the target system and not by postinst scripts that could be run on the host. For example, an (admittedly somewhat unscientific) survey on my desktop machine suggests that fontconfig, samba and cups, at least, are creating files in /var/cache at run time with contents that you wouldn't be able to predict in advance. (Apt also uses /var/cache as its download area, but I guess if you have a read-only roofs then you aren't going to be running apt very much so that one probably isn't an issue.) I wasn't able to immediately identify any files in there that would be obvious candidates for creating in a postinst and then leaving untouched afterwards. p.