Re: [tlug] Computer fails to boot

["David Bernat" <dbernat@example.com>]

"Stephen J. Turnbull" <stephen@example.com> wrote:

>    sudo mount -o remount,rw /dev/sda1
>
>instead:

ubuntu@example.com:~$ sudo mount -o remount,rw /dev/sda1
mount: can't find /dev/sda1 in /etc/fstab or /etc/mtab

>Almost certainly not.  You do not need to be able to write to a disk
>to run a program from a file on that disk, for one thing.  For
>another, since (under Knoppix, I guess?) it's mounted rw, you probably
>don't have hardware problems that prevent mounting rw under your
>HDD-based installation, either.  You won't be able to find that out
>until you successfully boot that system, though.
>
>The problem is that somehow /bin/sh -> /bin/dash has been either
>trashed or set to non-executable, and the kernel refuses to load and
>execute it.  You need to su and reset those permissions on dash:
>
>chmod 0755 /bin/dash

ubuntu@example.com:~$ chmod 0755 /bin/dash
chmod: changing permissions of `/bin/dash': Operation not permitted
ubuntu@example.com:~$ sudo chmod 0755 /bin/dash
ubuntu@example.com:~$

Could the error messages provided previously be a red herring?

/etc/fstab now has the contents

unionfs / unionfs rw 0 0
tmpfs /tmp tmpfs nosuid,nodev 0 0
/dev/sda5 swap swap defaults 0 0

/home/david/fstab on the internal hard disk has the contents

# /etc/fstab: static file system information.
#
#  -- This file has been automaticly generated by ntfs-config --
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>

proc /proc proc defaults 0 0
# Entry for /dev/sda1 :
UUID=9b6119b9-a271-4e66-af2d-9ba2fb3509c4 / ext3
nouser,relatime,errors=remount-ro,atime,auto,rw,dev,exec,suid 0 1
# Entry for /dev/sda5 :
UUID=6298b9dd-6c63-41a2-a9f3-7f2e19cd2b52 none swap sw 0 0
/dev/scd0 /media/cdrom0 udf,iso9660
/dev/sdb1 <mount point> ntfs-3g force 0 0

Why has /etc/fstab suddenly been truncated to only links to the swap
partition? Editing /etc/fstab with Kate in sudo mode to create the same
fstab file as in /home/david, saving the file, and then rebooting leaves
/etc/fstab with links to only the swap partition.

I am now going to reboot the laptop to test whether chmod hyad any effect.