From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from pb-smtp2.pobox.com ([64.147.108.71]:54111 "EHLO pb-smtp2.pobox.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727231AbeILW5A (ORCPT ); Wed, 12 Sep 2018 18:57:00 -0400 Received: from pb-smtp2.pobox.com (unknown [127.0.0.1]) by pb-smtp2.pobox.com (Postfix) with ESMTP id 5299110E2F7 for ; Wed, 12 Sep 2018 13:51:22 -0400 (EDT) Received: from pb-smtp2.nyi.icgroup.com (unknown [127.0.0.1]) by pb-smtp2.pobox.com (Postfix) with ESMTP id 4BE1110E2F6 for ; Wed, 12 Sep 2018 13:51:22 -0400 (EDT) Received: from [192.168.1.20] (unknown [73.55.237.65]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by pb-smtp2.pobox.com (Postfix) with ESMTPSA id B740A10E2F5 for ; Wed, 12 Sep 2018 13:51:21 -0400 (EDT) To: linux-fsdevel@vger.kernel.org From: Jonathan Busby Subject: How to access "upper" directory of overlayfs programatically Message-ID: <5B995210.1030104@pobox.com> Date: Wed, 12 Sep 2018 12:51:12 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Hello. I'm new to this list and I don't know if this is the right forum for my question, but, I've asked this same question on many forums and never received an answer -- please don't flame me. I have a Debian based Linux live system which is running out of RAM and was booted without the "persistent" boot option, so the capser-rw filesystem was never created. I wish to gain access to the "upper" directory of the overlayfs filesystem in the casper init scripts initramfs "/cow/upper" filesystem so that I may programatically save the filesystem, hopefully without having to re-implement cp. I know how to commit the changes of a Debian based live CD session to a storage device, but only if the live session in question was booted with the "persistent" option. I've looked at the overlayfs source code but I still can't figure out how to accomplish what I want. I'm sorry if this is stupid question -- hopefully it's not. Thank you, Jonathan