I'm having a problem with Ubuntu that I'm finding hard to troubleshoot for reasons that will become clear:

reboot

-bash: /sbin/reboot: Input/output error

dmesg

-bash: /bin/dmesg: Input/output error

ps -e

ps: error while loading shared libraries: /lib/libproc-3.2.8.so: cannot read file data: Input/output error

lsof

-bash: /usr/bin/lsof: Input/output error

fsck

-bash: /sbin/fsck: Input/output error

badblocks

-bash: /sbin/badblocks: Input/output error

So I can't see what is going on, and I can't remotely reboot. What can I do to get to the bottom of this?

Interestingly:

init 0

Segmentation fault

I can cat /var/syslog but not /var/log/messages or several other important files. less and more don't work, neither do tail or head, etc.