From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vladimir Davydov Subject: Re: [PATCH 00/19] pramfs Date: Sun, 8 Sep 2013 13:05:32 +0400 Message-ID: <522C3DDC.4090209@parallels.com> References: <522AE04C.6000002@gmail.com> <522B52BA.6030202@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Cc: richard -rw- weinberger , Linux FS Devel , Linux Kernel To: Marco Stornelli Return-path: Received: from relay.parallels.com ([195.214.232.42]:45120 "EHLO relay.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752382Ab3IHJFd (ORCPT ); Sun, 8 Sep 2013 05:05:33 -0400 In-Reply-To: <522B52BA.6030202@gmail.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On 09/07/2013 08:22 PM, Marco Stornelli wrote: > Il 07/09/2013 16:58, richard -rw- weinberger ha scritto: >> On Sat, Sep 7, 2013 at 10:14 AM, Marco Stornelli >> wrote: >>> Hi all, >>> >>> this is an attempt to include pramfs in mainline. At the moment pramfs >>> has been included in LTSI kernel. Since last review the code is more >>> or less the same but, with a really big thanks to Vladimir Davydov and >>> Parallels, the development of fsck has been started and we have now >>> the possibility to correct fs errors due to corruption. It's a "young" >>> tool but we are working on it. You can clone the code from our repos: >>> >>> git clone git://git.code.sf.net/p/pramfs/code pramfs-code >>> git clone git://git.code.sf.net/p/pramfs/Tools pramfs-Tools >> >> I'm a bit confused, what kind of non-volatile RAM is your fs targeting? >> Wouldn't it make sense to use pstore like >> arch/powerpc/platforms/pseries/nvram.c does? >> > > Usually battery-backed SRAM, but actually it can be used in any piece > of ram directly accessible and it provides a normal and complete fs > interface. Usually I do the fs test remapping my system ram. You can > find documentation here: > > http://pramfs.sourceforge.net I'd like to add that in contrast to pstore, pramfs allows storing any files in it, not only system logs. This can be of value even on machines w/o special devices like sram/nvram: one can store data that should be quickly restored after reboot in conventional ram and use kexec to boot to a new kernel. One of the use cases of this could be checkpointing time-critical services to ram (using criu.org) to be quickly restored after a kernel update providing almost zero-downtime. > > Marco