From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yann E. MORIN Date: Sun, 23 Jul 2017 12:31:47 +0200 Subject: [Buildroot] [PATCH 16/20] system: separate sysv and systemd parts of the skeleton In-Reply-To: <75f5daaf-c750-3f24-670e-ab470d845b16@mind.be> References: <430c46f8-bb5d-a2bf-3695-6822609e0a2c@mind.be> <75f5daaf-c750-3f24-670e-ab470d845b16@mind.be> Message-ID: <20170723103147.GF26998@scaer> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net On 2017-07-23 02:13 +0200, Arnout Vandecappelle spake thusly: > > > On 23-07-17 02:08, Arnout Vandecappelle wrote: > > > > On 18-07-17 19:25, Yann E. MORIN wrote: > >> systems does not like that the content of /var be symlinks to /tmp, > > systemd > > > >> especially journald that starts before /tmp is mounted, and thus the > >> journal files are hidden from view, which causes wuite a bit if fuss... > > quite > >> Instead, move the current /var to a sysv-only skeleton. > >> > >> systemd at install time will create the /var content it needs, so we > > I guess systemd will also create a tmpfs on /var? > > Seems the following sentence got dropped: > > What happens when a package installs something in /var? Since we do not (yet) support a read-only root filesystem for systemd, and that systemd does _not_ automatically mount anything on /var, we always have /var that is writable, and thus whatever a package installs in /var at build time is in /var at runtime. Now, see the followup patches, that add support for a read-only rootfs with systemd: fs: add pre- and post-command hooks system: make systemd work on a read-only rootfs Even though the code for each is relatively simple, there is a *lot* of explanations in there about /var handling on a read-only rootfs with systemd. But again, so far, we only ever supported systemd on a read-write rootfs. Regards, Yann E. MORIN. -- .-----------------.--------------------.------------------.--------------------. | Yann E. MORIN | Real-Time Embedded | /"\ ASCII RIBBON | Erics' conspiracy: | | +33 662 376 056 | Software Designer | \ / CAMPAIGN | ___ | | +33 223 225 172 `------------.-------: X AGAINST | \e/ There is no | | http://ymorin.is-a-geek.org/ | _/*\_ | / \ HTML MAIL | v conspiracy. | '------------------------------^-------^------------------^--------------------'