[uxbod]

Two things :-

1) apt-get install sysstat <- that will install iostat for you
2) Hmmm, looks like the password is incorrect for the zimbra_logger database.

So, run the following :-

su - zimbra
zmlocalconfig -s | grep -i mysql | grep -i logger

You should see the password for that database. You can then run

mysql --socket=/opt/zimbra/logger/db/mysql.sock -p

Enter the password and see if it connects you. If not you can then follow Resetting LDAP & MySQL Passwords - Zimbra :: Wiki