Do i have to upgrade bitcoind to the last version or it doesn't matter? And how i do that?
It uses the PPA, so simply typing this will update it to the latest:
sudo apt-get update
sudo apt-get upgrade
bitcoind stop
bitcoind start
30GB is cutting it close right now. Not sure how much longer these will last:
root@Morblias:~# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/simfs 30G 27G 3.5G 89% /