Bug 525319 - LiveCD boot gets stuck during dmsetup?
Summary: LiveCD boot gets stuck during dmsetup?
Alias: None
Product: Fedora
Classification: Fedora
Component: dracut
Version: rawhide
Hardware: All
OS: Linux
Target Milestone: ---
Assignee: Harald Hoyer
QA Contact: Fedora Extras Quality Assurance
Depends On:
Blocks: F12Beta, F12BetaBlocker
TreeView+ depends on / blocked
Reported: 2009-09-23 21:54 UTC by Warren Togami
Modified: 2009-09-28 02:19 UTC (History)
5 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Last Closed: 2009-09-28 02:19:24 UTC

Attachments (Terms of Use)

Description Warren Togami 2009-09-23 21:54:39 UTC

September 23rd, 2009 nightly LiveCD gets stuck here.  Boot with "quiet rhgb" removed and add "rdinitdebug" within KVM with emulated ISO.

+ [ -n  -a -n /LiveOS/overlay-fedora-livecd--i686-200909231707- ]
+ dd if=/dev/null of=/overlay bs=1024 count=1 seek=524288
+ losetup /dev/loop4 /overlay
+ blockdev --getsize /dev/loop3
+ dmsetup create live-rw
+ echo 0 6291456 snapshot /dev/loop3 /dev/loop4 p 8

echo 0 `blockdev --getsize $BASE_LOOPDEV` snapshot $BASE_LOOPDEV $OVERLAY_LOOPDEV p 8 | dmsetup create live-rw

harald suspects that dmsetup might not be working anymore?
Warren's last working LiveCD was rawhide September 21st.

* Mon Sep 21 2009 Peter Rajnoha <prajnoha@redhat.com> - 2.02.52-3
- Enable udev synchronisation code.
- Install default udev rules for device-mapper and LVM2.
- Add BuildRequires: libudev-devel.
- Add Requires: libudev (to check udev is running).
- Add Requires: util-linux-ng (blkid used in udev rules).

Might not be related, but this is the only mention of device-mapper in %changelog after the 21st.  device-mapper and kernel did not change since then.

Comment 1 Harald Hoyer 2009-09-23 22:01:21 UTC
lvm seems to be broken in dracut, see also bug 525015

Comment 2 Harald Hoyer 2009-09-23 23:57:52 UTC
Please test


Comment 3 Alasdair Kergon 2009-09-24 00:14:32 UTC
That's the long-overdue RPM to enable full udev support.

Can someone point us to the sequence of lvm/dm commands being run here and whether the normal udev rules are in place with udev running or not?

Comment 4 Harald Hoyer 2009-09-24 00:23:09 UTC
dracut-002-7.gitb9c4654a.fc12 has all rules files, shared libs and the dmeventd and is supposed to fix this.

Comment 5 Alasdair Kergon 2009-09-24 00:52:19 UTC
Fingers crossed it works now...

I've located the source, so if not, we can attempt to isolate and reproduce problems outside the dracut environment.

Comment 6 Warren Togami 2009-09-24 01:47:37 UTC
I put dracut-002-7.gitb9c4654a.fc12 into a livecd and it boots in KVM successfully.  Will try LiveUSB with tomorrow's nightly live image.

Comment 7 Adam Williamson 2009-09-24 07:50:02 UTC
should block Beta, not just final release. will test tomorrow myself too.

Fedora Bugzappers volunteer triage team

Comment 8 Peter Rajnoha 2009-09-24 08:43:06 UTC
Well, when using those new device-mapper/lvm2 packages with udev synchronisation enabled (and using kernels >= 2.6.31), then dmsetup/lvm2 process expects the notification after device resume/rename/remove and waits for it! (so we're sure that all udev processing is finished and we can continue with dmsetup/lvm2 command processing)

You can disable this by using "--noudevsync" option (in dmsetup as well as LVM2 commands).

There's also a new setting in lvm.conf called udev_sync with which you can enable/disable this for LVM2 globally.

But when you decide to use udev synchronisation, you must include the logic that is in 95-dm-notify.rules udev rules into dracut (those rules are part of device-mapper package)! This one unlocks the waiting process. It's just this rule that's most important:

ENV{DM_COOKIE}=="?*", RUN+="$env{DM_SBIN_PATH}/dmsetup udevcomplete $env{DM_COOKIE}"

(...change the DM_SBIN_PATH to where you have dmsetup binary installed..)

This synchronisation is automatically turned off for older kernels < 2.6.31, because we do not provide support for important DM_COOKIE env var within udev events there.

(..it is also turned off automatically when we detect that udev is not running, but that's just for complete information :))

Comment 9 Peter Rajnoha 2009-09-24 08:45:34 UTC
(DM_COOKIE env var is sent from kernel directly, so no need for any extra rules to get this one)

Comment 10 Adam Williamson 2009-09-25 15:39:04 UTC
this was changed again, lvm and dracut both being reverted: warren and I will test and confirm 20090925 rawhide live images boot, and close the bug if so.

Fedora Bugzappers volunteer triage team

Comment 11 Adam Williamson 2009-09-28 02:19:24 UTC
all reports say 20090925+ builds work, so closing this.

Fedora Bugzappers volunteer triage team

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