Server Won't Start

[tjgc]

I have been trying to start my server recently but I can't get it to start. Whenever I try to open it, in the console it says

Server starting, setting up fifo connections and writing server ready.
sed: couldn't open temporary file /home/minecraft/server/sedG1BDay: No space left on
 device

Is there any way to delete big files or anything to make my server able to start. 

PS: I have the Standard server plan

[tjgc]

Also if it helps in the stats section of the website it says that the disk space is 20.96 GB out of 20 GB