Getting the "No space left on device" message when there is a lot of free disk space could indicate that all available Inodes have been exhausted.

Resolution

1. Check available Inodes with the command below:

df -i

Sample command output:

Filesystem     Inodes IUsed  IFree IUse% Mounted on
/dev/sda6      776720 776720     0   100% /
udev                0     0      0     -  /dev
tmpfs          256893     2 256891    1%  /dev/shm
/dev/sda1       33864    40  33824    1%  /boot

2. If you have IUse% at 100 or near, then the available Inodes have been exhausted. Usually, the reason for this could be a huge number of small files, and deleting or compressing them should release the Inodes and resolve the issue.