Openstack 如何修改已经创建实例的大小

比如已经创建的实例，我想修改它的默认内容，我在dashboard上面修改调整云主机大小,但是没有效果。

网上有人说这是实例的迁移，需要设置nova用户到其他计算节点的免登录，但是按照以前的免登录设置，总是无法成功
(已经把2台机器上.ssh和其下的文件权限都暴力的改成了777)

[mw_shl_code=applescript,true]sh-4.2$ ssh computer3 -v
OpenSSH_6.6.1, OpenSSL 1.0.1e-fips 11 Feb 2013
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 56: Applying options for *
debug1: Connecting to computer3 [1.185.74.213] port 22.
debug1: Connection established.
debug1: identity file /var/lib/nova/.ssh/id_rsa type 1
debug1: identity file /var/lib/nova/.ssh/id_rsa-cert type -1
debug1: identity file /var/lib/nova/.ssh/id_dsa type -1
debug1: identity file /var/lib/nova/.ssh/id_dsa-cert type -1
debug1: identity file /var/lib/nova/.ssh/id_ecdsa type -1
debug1: identity file /var/lib/nova/.ssh/id_ecdsa-cert type -1
debug1: identity file /var/lib/nova/.ssh/id_ed25519 type -1
debug1: identity file /var/lib/nova/.ssh/id_ed25519-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_6.6.1
debug1: Remote protocol version 2.0, remote software version OpenSSH_6.6.1
debug1: match: OpenSSH_6.6.1 pat OpenSSH_6.6.1* compat 0x04000000
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-ctr hmac-md5-etm@openssh.com none
debug1: kex: client->server aes128-ctr hmac-md5-etm@openssh.com none
debug1: kex: curve25519-sha256@libssh.org need=16 dh_need=16
debug1: kex: curve25519-sha256@libssh.org need=16 dh_need=16
debug1: sending SSH2_MSG_KEX_ECDH_INIT
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ECDSA 23:1b:a9:79:d1:b7:d9:6e:5c:4c:3e:b3:38:c9:c5:0f
debug1: Host 'computer3' is known and matches the ECDSA host key.
debug1: Found key in /var/lib/nova/.ssh/known_hosts:1
debug1: ssh_ecdsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: Roaming not allowed by server
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic,password
debug1: Next authentication method: gssapi-keyex
debug1: No valid Key exchange context
debug1: Next authentication method: gssapi-with-mic
debug1: Unspecified GSS failure.  Minor code may provide more information
No Kerberos credentials available

debug1: Unspecified GSS failure.  Minor code may provide more information
No Kerberos credentials available

debug1: Unspecified GSS failure.  Minor code may provide more information

debug1: Unspecified GSS failure.  Minor code may provide more information
No Kerberos credentials available

debug1: Next authentication method: publickey
debug1: Offering RSA public key: /var/lib/nova/.ssh/id_rsa
debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic,password
debug1: Trying private key: /var/lib/nova/.ssh/id_dsa
debug1: Trying private key: /var/lib/nova/.ssh/id_ecdsa
debug1: Trying private key: /var/lib/nova/.ssh/id_ed25519
debug1: Next authentication method: password
nova@computer3's password: [/mw_shl_code]