一体机dbca建库报错：
Cluster Node(s)[dm01dbadm01] are not accessibleCheck if these nodes are accessible using ssh/rshand have Oracle Grid Infrastructure running.Database Instance may not come up on these nodes.Do you want to continue?
检查ssh
在两节点间用ssh登录进行测试，无问题
ssh dm01dbadm01 ---ok
ssh dm01dbadm02 ---ok检查dbca日志
执行以下语句报错:
/usr/bin/ssh -o FallBackToRsh=no -o PasswordAuthentication=no -o StrictHostKeyChecking=yes -o NumberOfPasswordPrompts=0 dm01dbadm01 -n /bin/true
No ECDSA host key is known for dm01dbadm01 and you have requested strict checking.
Host key verification failed.
从报错看requested strict checking，StrictHostKeyChecking=yes去掉是否可行？
/usr/bin/ssh -o FallBackToRsh=no -o PasswordAuthentication=no -o NumberOfPasswordPrompts=0 postgres01 -n /bin/true
---ok什么是StrictHostKeyChecking
https://www.ibm.com/docs/en/zos/2.2.0?topic=program-host-key-checking
In host key checking, ssh automatically maintains and checks a database containing identification for all hosts it has ever been used with. Host keys are stored in in the user's home directory. Additionally, the file is automatically checked for known hosts. Any new hosts can be automatically added to the user's file. If a host's identification changes, ssh warns about this and disables password authentication to prevent server spoofing or man-in-the-middle attacks, which could otherwise be used to circumvent the encryption. The ssh_config keyword StrictHostKeyChecking can be used to control logins to machines whose host key is not known or has changed. The keyword is described in StrictHostKeyChecking. ~/.ssh/known_hosts/etc/ssh/ssh_known_hosts
从以上信息可以看到他是一种安全特性，用于校验登录主机的key值是否存在~/.ssh/known_hosts中，不存在则拒绝登录的主机进行连接。
检查~/.ssh/known_hosts
dm01dbadm01.oracle.com,172.16.10.99 ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBE/4gy61JdwaX7+22v4/hgM7xccSEI0GBEyS+sGf7ga2eON3sOMnWLJV/iD3t9oaWXhTUXVLkZDJwA1BCqDxUPA=
dm01dbadm02.oracle.com,172.16.10.100 ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBE/4gy61JdwaX7+22v4/hgM7xccSEI0GBEyS+sGf7ga2eON3sOMnWLJV/iD3t9oaWXhTUXVLkZDJwA1BCqDxUPA=
检查authorized_keys
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDZfGCZokZyX+IalteygNpvKGzY/5J4GaZXsYFXFXLGq34Fp3yig7yxQvG38SqfOWoc5z7FpBBQfFBczztRBgD2MSE/09PS7GCA68oAWek7+L+F9bJMrD5KcVCD3sw7OkGneVOk9u5ubNIeQL1Kx7dVPIZlA+UphYEI5IwpuezONNC18qqJxSaUfpQoa6NAuOzvDocQhvkK2pg/MftzoCAId2BXe7byUkCIIl693y3WFqTjpR9BEovJQB14QXsc7AP4eXb9Insh31mD0aUK2LhdDIOm/T2+3etEYbikYSL28VCpBDmKp3AbErKfFg4oyvawGBhghn+oiCSt+KNetSzb oracle@dm01dbadm02.oracle.com
ssh-rsa ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC1RnJR9tk9mKWGqVGyVmbBzMUu8WPl3P8PA5dGccwUQZW+HFtzej4YAL3LWIInLeLqaCNSvIVLNHhaztL0zBzTrN+nzszFbMWgQME79j6aC3VFvyzLvk9bnPIPtCqljwdM26ufoCAslGLOtDkkwFgBvVFU3Z3gR6ithlTHfRlh7TRQc5lH44JOmkqH/DvaU/Md3eTDOWGxG4zrwBSqOU1zSXEaKhpnM+ZfsMQ3stzmp+ctXGY/wVe0QstTGPSgfraCzHDCJyPNLobi30dbM1Q22Ok1hkXHtNEs0SWAh87/mJV6gLCJK3WuvnPPcTnlS8LE2jI9/iWUu/g9FwilS7hr oracle@dm01dbadm01.oracle.com
通过authorized_keys、known_hosts可以看到key信息记录为主机名对应的信息，而一体机安装过程中识别的是管理ip所对应的主机名。
解决办法：
复制authorized_keys、known_hosts中相同的条目，将主机名中的域名去掉即可。
其他可能错误：
1.Permission denied (publickey,password)
chmod 600 .ssh/authorized_keys chmod 700 .ssh2.密码过期
chage -l oracle/grid chage -M -1 oracle/grid
