ubuntu "No space left on device" but there is tons of space

I am getting the "No space left on device" error for pretty much anything i try to do. Even using tab to autocomplete a command! but when i do df -h i get: ubuntu@ip-10-0-2-108:~$ df -h Filesystem Size Used Avail Use% Mounted on /dev/xvda1 99G 6.5G 88G 7% / udev 3.7G 8.0K 3.7G 1% /dev tmpfs 1.5G 184K 1.5G 1% /run none 5.0M 0 5.0M 0% /run/lock none 3.7G 0 3.7G 0% /run/shm none 100M 0 100M 0% /run/user /dev/xvdb 414G 199M 393G 1% /mnt overflow 1.0M 1.0M 0 100% /tmp which to me looks like there is tons of space. df -i also looks similar: ubuntu@ip-10-0-2-108:~$ df -i Filesystem Inodes IUsed IFree IUse% Mounted on /dev/xvda1 6553600 94227 6459373 2% / udev 951353 393 950960 1% /dev tmpfs 953649 274 953375 1% /run none 953649 3 953646 1% /run/lock none 953649 1 953648 1% /run/shm none 953649 1 953648 1% /run/user /dev/xvdb 27525120 11 27525109 1% /mnt overflow 953649 12 953637 1% /tmp I am on an Amazon EC2 ubuntu 12.04 instance. Here are some examples of the error popping up: ubuntu@ip-10-0-2-108:~$ sudo crontab -e /tmp/crontab.RvYjrR/crontab: No space left on device ubuntu@ip-10-0-2-108:~$ ls /va (hit tab for autocomplete) -bash: cannot create temp file for here-document: No space left on device -bash: cannot create temp file for here-document: No space left on device however the server seems to be running and everything seems to be working. what on earth is going on??