Documentation #8549
closedCeph installation pre-flight problem with ssh-copy-id
0%
Description
http://ceph.com/docs/master/start/quick-start-preflight/#ceph-node-setup
The use of ssh-copy-id in the above document may not work in some cases. Here's a scenario that demonstrates this:
1. I locked two vpm machines. In this case vpm003 and vpm082.
2. I ssh'ed as ubuntu to vpm003 and vpm082 on two separate windows.
3. I created a user named ceph on vpm082. I plan to install the program ceph on vpm082 from vpm003.
4. I performed the ssh-keygen as specified in this page. I have access from my machine to vpm003 and vpm082. As far as I can tell, there is not an ssh link between vpm003 and vpm082 yet.
5. ssh-copy-id now returns: Permission denied.
What we have here is a chicken-and-egg situation. I am running ssh-copy-id to set up the connection, but the connection does not work because it is not set up yet.
The workaround that I have been using in this case is to cat ~/.ssh/id_rsa.pub on vpm003 and to pick and paste that entry into ~/.ssh/authorized_keys on vpm082. Ssh connections after that work fine.
This problem I can foresee also occurring if I physically am sitting at two machines with no ssh connection established yet. This may be a common situation in the real world.
Updated by Anonymous almost 10 years ago
I think that the ssh-copy-id may work if there is a .ssh/authorized_keys file already set up on the 'copy to' machine
Updated by John Wilkins almost 10 years ago
The instruction is to create passwordless ssh between the admin node and the ceph nodes. It sounds to me like you are setting up vpm003 as an admin node and vpm 082 as a Ceph node, and that is why you want to install ceph on vpm082 from vpm003. In that case, you'd want to run ssh-keygen from the admin node vpm003, not your local host. Steps 4 and 5 are to be done from the admin node, which sounds like it is vpm003 and not your localhost. If you are running from your local host, it won't work.
Are you suggesting that step 5 must also clearly state "from the admin node"?
Updated by Zac Dover over 4 years ago
- Status changed from New to Closed
This bug has been judged too old to fix. This is because either it is either 1) raised against a version of Ceph prior to Luminous, or 2) just really old, and untouched for so long that it is unlikely nowadays to represent a live documentation concern.
If you think that the closing of this bug is an error, raise another bug of a similar kind. If you think that the matter requires urgent attention, please let Zac Dover know at zac.dover@gmail.com.