Bug 670370

Summary:	sys-fs/mdadm - mdadm-last-resort prevents logins, brings down services
Product:	Gentoo Linux	Reporter:	Carsten Böcker <news>
Component:	Current packages	Assignee:	Gentoo's Team for Core System packages <base-system>
Status:	RESOLVED FIXED
Severity:	normal	CC:	news, systemd
Priority:	Normal
Version:	unspecified
Hardware:	All
OS:	Linux
See Also:	https://bugs.gentoo.org/show_bug.cgi?id=670472
Whiteboard:
Package list:		Runtime testing required:	---
Bug Depends on:	670472
Bug Blocks:
Attachments:	emerge --info journalctl -b with loglevel debug

Description Carsten Böcker 2018-11-05 14:02:53 UTC

Created attachment 554130 [details]
emerge --info

After upgrade to systemd-239-r2 it was impossible to login if I waited to long or partitions are not mounted and services not running if I login fast enough.

After searching a while I think I found the reason.

systemd has a job mdadm-last-resort which seems to be allways called and starts to unmount all mdadm-devices and also stopping nearly all services.

I found the solution in a debian-bug-report:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=892257

Applying the patch mentioned to /lib/systemd/system/mdadm-last-resort\@.service resolved the boot-problems.

Relevant part of the Patch is:
+-Conflicts=sys-devices-virtual-block-%i.device
++ConditionPathExists=!/sys/devices/virtual/block/%i/md/sync_action

Appended output of emerge --info and also output of journalctl -b with LogLevel=debug from a failed boot

Comment 1 Carsten Böcker 2018-11-05 14:04:08 UTC

Created attachment 554132 [details]
journalctl -b with loglevel debug

Comment 2 Mike Gilbert gentoo-dev

2018-11-05 15:36:21 UTC

This is a bug in sys-fs/mdadm. It has been fixed in the latest version (4.1).

Comment 3 Carsten Böcker 2018-11-05 15:54:56 UTC

Thanks for the information. I added ~adm64-keyword for mdadm and 
mdadm-last-resort\@.service has the change and everything works as expected.

Perhaps mdadm-4.1 should be stabilized ..... but perhaps I am the only one with systemd and mdadm so it is not necessary anymore

Comment 4 Mike Gilbert gentoo-dev

2018-11-05 16:01:25 UTC

Agreed, we should stabilize 4.1 or backport the change to the current stable version.

Comment 5 Carsten Böcker 2018-11-05 16:10:24 UTC

Yes backporting would be a very good Idea. I can confirm that this change is working with current stable mdadm, it is a small change and perhaps it saves someone some time to debug this startup-problems.