syslog contains a whole lot of ^@

[Colin Law]

On 16 May 2016 at 15:34, Ian A Taylor <iat at st-andrews.ac.uk> wrote:
> Sir/Madam
>
> I have Ubuntu box that runs Ubuntu 14:04
>
> lsb_release -a
> No LSB modules are available.
> Distributor ID:    Ubuntu
> Description:    Ubuntu 14.04.4 LTS
> Release:    14.04
> Codename:    trusty
>
> uname -a
> Linux nabucodonosor 3.13.0-86-generic #130-Ubuntu SMP Mon Apr 18 18:27:15
> UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
>
> However it is only booting up correct on the odd occasion.
>
> When it fails it does seem pingable and nmap says port 22 is open but it
> will not allow ssh
>
>
> ssh -v
> OpenSSH_6.6.1, OpenSSL 1.0.1f 6 Jan 2014
> debug1: Reading configuration data /etc/ssh/ssh_config
> debug1: /etc/ssh/ssh_config line 19: Applying options for *
> debug1: Connecting to nabucodonosor [138.251.106.222] port 22.
> debug1: connect to address 138.251.106.222 port 22: No route to host
> ssh: connect to host nabucodonosor port 22: No route to host
>
> In /var/log/syslog there are a whole lot of blue ^@
> They seem only to appear when system fails to allow ssh
>
> The graphic login screen also fails to appear
>
> Does anyone know what these blue ^@ mean ?

That usually means means a disaster of some sort has occurred and the
file has been left with garbage at the end.

If you run memtest from the boot menu for a couple of hours is it ok?

If you can get it to boot from its own disk, in a terminal run
sudo touch /forcefsck
and reboot, that will tell it to check the disk on boot.

Can you boot from a live Ubuntu image on USB or DVD?

Colin