Bug 322969 – sys-fs/lvm2: dmeventd fails to start in early boot runlevel with lvm due to read-only /var/run

• Product: Gentoo Linux
• Status: RESOLVED FIXED

[Description Xake 2010-06-06 10:33:24 UTC]

I have a system where every system volume is using lvm2 placed on top of a mdraid,RAID0 except /home placed on a lvm2 on another harddrive.
I have a genkernel created ramdisk that mount my root. This ramdisk also starts the raid and the LVMs (i.e. domdadm dolvm).

I use openrc and have added lvm and dmeventd to my boot runlevel.
The problem here is that I noticed that dmeventd fails to start with "Child exited with status 5", but later in runlevel default openrc tries again and starts dmeventd without problem.

Looking at the deps of the initscripts you pretty soon realise that the scripts try to start init.d scripts in the following order:

dmeventd
lvm (has "after dmeventd" and "use dmeventd" and "before fsck")
fsck
root

The problem here is that exit status 5 for dmevent means PID_FAILURE, and in this case it is that the pid file resides on a read only file system.
But according to the order of dependencies if you need lvm dmeventd will newer start before root (or rather wherever you have /var/run) is mounted rw which means that dmeventd will always fail due to this.

Portage 2.2_rc67 (hardened/linux/amd64/10.0, gcc-4.4.4, glibc-2.11.1-r0, 2.6.34-gentoo x86_64)
=================================================================
System uname: Linux-2.6.34-gentoo-x86_64-Intel-R-_Core-TM-_i7_CPU_920_@_2.67GHz-with-gentoo-2.0.1
Timestamp of tree: Sun, 06 Jun 2010 09:00:20 +0000
ccache version 2.4 [disabled]
app-shells/bash:     4.1_p7
dev-java/java-config: 2.1.11
dev-lang/python:     2.6.5-r2, 3.1.2-r3
dev-python/pycrypto: 2.1.0
dev-util/ccache:     2.4-r8
dev-util/cmake:      2.8.1-r2
sys-apps/baselayout: 2.0.1
sys-apps/openrc:     0.6.1-r1
sys-apps/sandbox:    2.2
sys-devel/autoconf:  2.13, 2.65
sys-devel/automake:  1.9.6-r3, 1.10.3, 1.11.1
sys-devel/binutils:  2.20.1-r1
sys-devel/gcc:       4.4.4-r2
sys-devel/gcc-config: 1.4.1
sys-devel/libtool:   2.2.7b
virtual/os-headers:  2.6.33
ACCEPT_KEYWORDS="amd64 ~amd64"
ACCEPT_LICENSE="*"
CBUILD="x86_64-pc-linux-gnu"
CFLAGS="-march=native -O2 -pipe -ggdb -mtune=native"
CHOST="x86_64-pc-linux-gnu"
CONFIG_PROTECT="/etc /usr/share/X11/xkb"
CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/env.d /etc/env.d/java/ /etc/fonts/fonts.conf /etc/gconf /etc/gentoo-release /etc/revdep-rebuild /etc/sandbox.d /etc/splash /etc/terminfo /etc/texmf/language.dat.d /etc/texmf/language.def.d /etc/texmf/updmap.d /etc/texmf/web2c"
CXXFLAGS="-march=native -O2 -pipe -ggdb -mtune=native"
DISTDIR="/var/portage/distfiles"
FEATURES="assume-digests distlocks fixpackages metadata-transfer news parallel-fetch preserve-libs protect-owned sandbox sfperms splitdebug strict test unmerge-logs unmerge-orphans userfetch"
GENTOO_MIRRORS="ftp://ftp.sunet.se/pub/os/Linux/distributions/gentoo"
INSTALL_MASK="*.la"
LANG="sv_SE.UTF-8"
LC_ALL="C"
LDFLAGS="-Wl,--as-needed -Wl,-O1 -Wl,--sort-common -Wl,--warn-once,--hash-style=gnu"
LINGUAS="sv en"
MAKEOPTS="-j10 -l10"
PKGDIR="/var/portage/packages"
PORTAGE_CONFIGROOT="/"
PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --compress --force --whole-file --delete --stats --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages"
PORTAGE_TMPDIR="/var/tmp"
PORTDIR="/var/portage"
PORTDIR_OVERLAY="/var/overlays/layman/java-overlay /var/overlays/layman/hardened-development /var/overlays/layman/gnome /var/overlays/layman/x11 /var/overlays/layman/mozilla /var/overlays/layman/gamerlay /var/overlays/mine"
SYNC="rsync://rsync.gentoo.org/gentoo-portage"
USE="X a52 aac accessibility acl acpi alsa amd64 amr amrnb amrwb applet archive asyncns avahi bash-completion bluetooth branding bzip2 cairo ccache cdaudio cdda cdr cleartype cli consolekit coverart cracklib crypt cups cxx dbus device-mapper devicekit devkit dhcpcd digitalradio dirac djvu dmraid dri dts dvd dvdr dvi eds encode eselect evo exif faac faad fat fbcondecor ffmpeg fftw flac fontconfig fuse gdbm gdm gdu gif gimp glib gmp gnome gnome-keyring gphoto2 gpm grammar graphite gsf gsm gstreamer gtk gudev hal hardened hpn ical iconv iconvacl icq icu id3tag idn ieee1394 iptc jabber jack java6 jingle jpeg jpeg2k justify kate kvm lcms libffi libnotify libsamplerate logrotate lvm lvm2 lzma mad maps math matroska md mdadm midi mms mmx mmxext mng moonlight mp2 mp3 mpeg mpi msn mtp mudflap multilib musepack musicbrainz nautilus ncurses network-cron networkmanager nfs nls nntp nptl nptlonly ntfs offensive ogg openal opencore-amr opengl openmp openntpd ots pam pango parted pcre pdf perl pic pidgin png policykit pppd pulseaudio python quicktime raw readline reflection rrdcgi samba sensord session smp sms speex spell spl sse sse2 ssl ssse3 startup-notification subversion svg sysfs test tex theora thesaurus threads tiff totem truetype udev unicode upnp urandom usb userlocales v4l2 vdpau vhook videos vim-syntax vorbis webkit wmf x264 xcb xcomposite xmp xmpp xorg xrandr xscreensaver xulrunner xv xvid xvmc zeroconf zlib" ALSA_CARDS="hda-intel" ALSA_PCM_PLUGINS="adpcm alaw asym copy dmix dshare dsnoop empty extplug file hooks iec958 ioplug ladspa lfloat linear meter mmap_emul mulaw multi null plug rate route share shm softvol" APACHE2_MODULES="actions alias auth_basic authn_alias authn_anon authn_dbm authn_default authn_file authz_dbm authz_default authz_groupfile authz_host authz_owner authz_user autoindex cache dav dav_fs dav_lock deflate dir disk_cache env expires ext_filter file_cache filter headers include info log_config logio mem_cache mime mime_magic negotiation rewrite setenvif speling status unique_id userdir usertrack vhost_alias" ELIBC="glibc" INPUT_DEVICES="evdev" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LINGUAS="sv en" QEMU_SOFTMMU_TARGETS="i386 x86_64" QEMU_USER_TARGETS="i386 x86_64" RUBY_TARGETS="ruby18" USERLAND="GNU" VIDEO_CARDS="nouveau" XTABLES_ADDONS="quota2 psd pknock lscan length2 ipv4options ipset ipp2p iface geoip fuzzy condition tee tarpit sysrq steal rawnat logmark ipmark dhcpmac delude chaos account" 
Unset:  CPPFLAGS, CTARGET, EMERGE_DEFAULT_OPTS, FFLAGS, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS

[Comment 1 Michael Weber (RETIRED) 2010-06-07 01:32:35 UTC]

@ sys-apps/openrc Maintainers: I've added you because i think you see this on a greater scale, since something's missing a writeable /var/run. A tmpfs over there might help.

[Comment 2 SpanKY 2010-06-07 09:43:10 UTC]

some services keep the fd open with /var/run files.  not many, but it is certainly more than zero.  perhaps with those we simply say "dont do it" though.

[Comment 3 Alasdair Kergon 2010-06-07 10:21:42 UTC]

Upstream, we decided not to use dmeventd until after everything else has been initialised, on the grounds that if something that dmeventd would handle fails at such an early stage of booting, you're likely to have serious problems that need manual intervention anyway.  vg/lvchange --sysinit skips stuff like that, then a later 'lvchange --monitor y --poll y ' starts it up.

[Comment 4 Robin Johnson 2010-06-09 06:34:42 UTC]

Ok, this will be going into 2.02.67-r1, moving all of dmeventd to AFTER lvm/device-mapper. Also uses --sysinit now for new early start/stop stuff.

[Comment 5 Robin Johnson 2010-06-09 22:41:52 UTC]

2.02.67-r1 in CVS.