[arch-general] rootfs remains in ro at boot on fresh install with new December ISO

[Dave Reisner]

On Mon, Dec 03, 2012 at 05:00:48PM +0000, LANGLOIS Olivier PIS -EXT wrote:
> Hi,
> 
> I hope it is not caused by the shortcut that I have taken to update my usb install key from november iso to december iso as described in the other thread.
> 
> The first symptom that I have observed is that dhcpcd isn't able to update /etc/resolv.conf
> 
> I am going to provide as much relevant info so you can tell me what to look for
> 
> 1. Installed from december iso on newly created GPT ext4 partitions
> 2. Bootloader GRUB2
> 3. Did a systemctl mask tmpfs as I am mounting a disk partition on /tmp from fstab
> 4. Double checked 2-3 times that all my mounts are rw in fstab

You'll want to actually provide your /etc/fstab as well as the output
of:

  systemctl status /

Right after booting...

> 5. Once logged, I have no problem doing "mount -o remount,rw /"
> 6. I have removed the ro kernel parameter option in grub.cfg (BTW, why is this used at all? I'm a little bit ignorant about Linux booting good practices). By doing so rootfs still remains ro.

'ro' is the default if neither 'rw' nor 'ro' are specified. If you want
your root to be mounted rw initially, you need to do 2 things:

1) explicitly add 'rw' to your kernel cmdline
2) include the fsck hook in your initramfs

Otherwise, it's left up to your /etc/fstab to ensure that it's remounted
properly.

> I am suspecting either systemd or the content of the initramfs. Until now, those are still black boxes to me. What should I look at to resolve my rootfs ro problem?

Strange suspicion... Without seeing it, I suspect your /etc/fstab is at
fault, simply because I've learned better than to trust anecdotal evidnce.

d