[systemd-devel] perform fsck on everyt boot

[Chris Murphy]

On Wed, Nov 20, 2019, 11:58 PM Belisko Marek <marek.belisko at gmail.com>
wrote:

> On Thu, Nov 21, 2019 at 7:25 AM Chris Murphy <lists at colorremedies.com>
> wrote:
> >
> > On Tue, Nov 12, 2019 at 3:52 AM Belisko Marek <marek.belisko at gmail.com>
> wrote:
> > >
> > > On Mon, Nov 11, 2019 at 4:47 PM Lennart Poettering
> > > <lennart at poettering.net> wrote:
> > > >
> > > > On Mo, 11.11.19 13:33, Belisko Marek (marek.belisko at gmail.com)
> wrote:
> > > > 65;5802;1c
> > > > > Hi,
> > > > >
> > > > > I'm using systemd 234 (build by yocto) and I've setup automount of
> > > > > sdcard in fstab. This works perfectly fine. But I have seen from
> time
> > > > > to time when system goes to emergency mode because sdcard
> filesystem
> > > > > (ext4) have an issue and cannot be mounted. I was thinking about
> > > > > forcing fsck for every boot. Reading manual it should be enough to
> set
> > > > > passno (6th column in fstab) to anything higher then 0. I set ti
> to 2
> > > > > but inspecting logs it doesn't seems fsck is performed. Am I still
> > > > > missing something? Thanks.
> > > >
> > > > Well, note that ext4's fsck only does an actual file system check
> > > > every now and then. Hence: how did you determine fsck wasn't started?
> > > >
> > > > Do you see the relevant fsck in "systemctl -t service | grep
> > > > systemd-fsck@"?
> > > I just saw in log:
> > > [  OK  ] Found device /dev/mmcblk1p1.
> > >         Mounting /mnt/sdcard...
> > > [    8.339072] EXT4-fs (mmcblk1p1): VFS: Found ext4 filesystem with
> > > invalid superblock checksum.  Run e2fsck?
> > > [FAILED] Failed to mount /mnt/sdcard.
> >
> > This isn't normal. Your effort should be on finding out why this
> > problem is happening in the first place. This doesn't strike me as the
> > (somewhat) ordinary case of unclean unmount, which results in journal
> > replay at next mount attempt. But something considerably more serious.
> Problem is it's very hard to reproduce and this is not rootfs just
> external SDcard for storing some data.
> If I hit this system goes to emergency mode and device is dead and I
> would like to prevent that in first place.
> IMO fsck should help to recover this issue and should continue without
> issues. Thanks.
>

Possibly adding nofail option in fstab will prevent startup from going into
rescue.target.

I'm skeptical of unattended use of fsck. That's what journal replay is for,
and if replay can't fix the problem, then the underlying problem needs to
be fixed rather than papered over with fsck.

You might consider testing this SDCard with f3, which will check for
corruption, and fake flash. Reformat, mount, f3write /mountpoint, f3read
/mountpoint.

I don't trust consumer SDCards for anything. I've had name brand stuff
fail.

The systemd journal should show evidence of either umount success or
failure for this SDCard on restart or shutdown. Do the corruptions only
happen on shutdowns? It both shutdown and restart? SDCards can get really
fussy, exhibiting corruptions, or just brick themselves, when power is
removed while writes are still happening internally. Cheaper flash may be
slower to flush to stable media. You can give it more time by manually
unmounting this SDCard before reboot or shutdown.


Chris Murphy
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