I am absolutely new to this stuff, please help on below error, shall be thankful

```
ubuntu@ip-172-31-18-75:~$ geth --testnet

```

> 
> I1025 10:12:44.731831 ethdb/database.go:83] Alloted 128MB cache and
>  1024 file handles to /home/ubuntu/.ethereum/testnet/chaindata Fatal:
>  Could not open database: write
>  /home/ubuntu/.ethereum/testnet/chaindata/111615.ldb: no space left on
>  device
> 
> 
>