If root cannot be remounted "rw" due to an issue, the status is falsely reported as "OK"
Seems the remount handler cannot fully identify the status from mount -o remount.
I had a small world of pain until I identified this issue, it would be good to verify if it applies to other mount issues as well.
The setup-alpine creates a ext4 filesystem with the “barrier=1” option.
When testing Alpine VMs on a older Xen host that still had a 2.6.18….
RHEL-based kernel there’s the issue that the devmapper/LVM cannot
correctly handle barriers.
Ext4 denies the remount to RW under this condition[*]. Nonetheless
the boot script that remounts root does report an OK state. There’s a
lot of ext errors if I manually try this.
I think the most important part in this is to identify holes in the
return code handling.
The bug in itself is only a small nuisance for me so far.
I can re-test or provide a test vm for this.
[*](and it doesn’t matter if you set “nobarrier” in your fstab, for
some reason. mount bug actually, can verify that manually if you do
mount o remount,nobarrier and cat /proc/mounts the arguments are
stacked. If you do a tune2fs and set nobarrier that way, it’ll work)
(from redmine: issue id 967, created on 2012-01-30)