----- Forwarded message from Dave Reisner <[email protected]> -----
> Date: Mon, 2 May 2011 12:09:54 -0400 > From: Dave Reisner <[email protected]> > To: Gerardo Exequiel Pozzi <[email protected]> > Subject: Re: [arch-projects] [RFC3][PATCH] [mkinitcpio] Cleanly stop udev >= > 168 as > recommended by upstream. > > On Mon, May 02, 2011 at 12:28:41PM -0300, Gerardo Exequiel Pozzi wrote: > > On 05/02/2011 11:23 AM, Thomas Bächler wrote: > > >Am 02.05.2011 16:00, schrieb Gerardo Exequiel Pozzi: > > >>N0: device-mapper/LVM udev rules must be parsed for initramfs creation > > >> to add OPTIONS+="db_persist" > > >Patch looks good now. > > Great! > > >I am unsure and confused why we would need this db_persist option. In > > >the past, we killed udev and the db completely and everything worked out > > >fine. What kind of state would need to be persistent? Is upstream adding > > >this option? > > We've never killed the DB on leaving early userspace because the DB > previously lived in /dev/.udev. We did a mount --move of /dev to > /new_root/dev and continued on our merry way. Nothing different with the > DB in /run/udev. We transfer that tmpfs over to the root and everything > is preserved. > > > Yes, that is what I not understand, If I am not wrong this was > > before devtmpfs times. > > Not sure where devtmpfs comes into play. This is all created by udevd in > userland regardless of the filesystem /dev is mounted on. > > > Maybe this is needed in case if rules on initramfs differs from real > > root. Dave can you ask to Kay on IRC about this? (I am going to my > > work now) Thanks. > > > > Seems to me like lvm2 is just a pain in the ass for udev all around. In > systemd, it's the only reason that a call to udevadm settle is required > during late bootup. Everything else can be handled as hotplug events as > they come up. > > Snippets from Kay... > > 11:52 kay » falconindy: only if you use --db-cleanup, and yes lvm > plays dirty tricks with udev and needs the db preserved > 11:54 kay » falconindy: they need to catch up with 2011 a bit though > and stop scanning /dev, or have crazy regexes in their > config files > 11:58 kay » falconindy: in the past we used to rm -rf /dev/.udev > in the real root > 11:59 falconindy » which i assume is a more of a sledgehammer approach > to what the cleanup does > 12:00 kay » falconindy: not that different, the db_persist just > adds a sticky bit to the db file > > So LVM is just a pain in the butt all around. State can be wiped for all > other devices and the rebuilt DB in later userspace doesn't contain > failed/unhandled events from the initramfs. > > dave > ----- End forwarded message ----- And i replied to Gerardo by mistake instead of the list... d
