Eucalyptus Ssh Can Not Login Solution

I used
to see the password first. If there is no password "aa", then use the following command.
euca-add-keypair aa > my.private
else delete password "aa" first or use another password.
euca-delete-keypair aa
you should change my.private file access privilege, like:
chmod 0600 my.private
then use euca-run-instance to run:
euca-run-instance -k aa -n 1 $emi
then I have seen ip of instance. use ssh to login:
ssh -i my.private root@ip

If you do not change my.private file access privilege, then it will report:

privilege 0644 is too open.
If you chmod after the report, ssh will not let you login. So change it before you want access your instance.