After creating an instance from CloudStack UI, I can see the VMs:
# virsh list --all
Id Name State
----------------------------------------------------
1 v-2-VM running
4 s-1-VM running
5 r-4-VM running
8 i-2-5-VM running
10 i-2-3-VM running
But when I try to start a console for an instance say i-2-5-VM, i get the following:
# virsh console i-2-5-VM
Connected to domain i-2-5-VM
Escape character is ^]
Hereafter the console hangs, not even the command prompt comes. Then i have to press Ctrl+] to come back to the shell. Additional information:
# virsh ttyconsole i-2-5-VM
/dev/pts/4
I can ping to it, but cannot ssh.
Please let me know, how can I login to my instance ?
Start the console from the CloudStack GUI rather than the command line.
Also if you want to see the details of the VM, you can install GUI tool virt-manager which will show you all the instances running on the KVM hypervisor and their all the details (nics, volumes, memory, state etc)
Related
My GCP VM instance was setup sometime back and all the services were working fine. However, suddenly from today I am not able to login via SSH and even an instance restart did not fix the issue. When checked the serial log, it seems to have stopped in this line,
[ 8.686861] intel_powerclamp: No package C-state
availableintel_powerclamp: No package C-state available[ 8.705723]
attempt to access beyond end of device [ 8.706721] sda1: rw=0,
want=41927608, limit=41927602 [[32m OK [0m] Started Security
Auditing Service.
Starting Update UTMP about System Boot/Shutdown...
32m OK [0m] Started Update UTMP about System Boot/Shutdown.
Starting Update UTMP about System Runlevel Changes...
32m OK [0m] Started Update UTMP about System Runlevel
ChanWelcome to emergency mode! AfterGive root password for maintenance
(or type Control-D to continue):
It won't proceed further to start SSH and other services, hence I am not able to login to the instance. Any help would be greatly appreciated.
Thanks in advance.
The error
No package C-state available
points to problems to mount the filesystem.
Did you try to follow the steps written in this other post ?
When you see Ctrl+D enter root password. Then enter mount -a to see in what line is the error.
Enter vi /etc/fstab and correct whatever is missing, save and reboot.
What you can do is logon to the serial console so you can interact with it. It will probably ask you for a root password and if you have not set that up, you can set that up through startup scripts.
I am unable to connect through SSH to my GCE instance. I was connecting without any problem, the only think I changes was my user name through top right corner of the browser then selected Change Linux Username.
When I try to ssh into my google engine via browser, I keep having following message in a endless loop:
When I try to ssh via cloud shell I also get following error message, (serial console output):
Permission denied (publickey).
ERROR: (gcloud.compute.ssh) [/usr/bin/ssh] exited with return code [255].
[Q] Is there any way to fix this problem? Since I have no access to the engine now, I don't know what to do.
However you could always get back access through serial console then from there you could internally y troubleshoot user/ssh issue.
1) $ gcloud compute instances add-metadata [INSTANCE_NAME] --metadata=serial-port-enable=1
You can then connect to the instance through the serial port
NOTE:The root password have must been already set in order to use the serial port
2)
$ gcloud compute connect-to-serial-port [INSTANCE_NAME]
If you never set the root password you could set it by adding a startup-script to your instance that will set a password as root by running the below command :
NOTE: the instance must be rebooted in order to run the startup script.
3) $ gcloud compute instances add-metadata [instance name] --metadata startup-script='echo "root:YourPasswdHere" | chpasswd'
Reboot the instance run the command on the step "2)" authenticate your self as root with the password that you set on the startup script in the step "3)" .
I had the same problem, It took me several days to figure out what was happening in my case.
To find out, I created a new instance from scratch and started making all modifications I've done to those that eventually couldn't connect to, one by one, exiting the ssh connection and re entering so as to test it.
I've tried it a couple of times, in both cases, the connection was impossible after uninstalling python (I only needed 3.7 version so I was uninstalling all others and installing that one I needed).
My command for uninstalling it was
sudo apt purge python2.7-minimal
and
sudo apt purge python3.5-minimal
I don't know if it was specifically because of deleting python, or because of using purge (in which case this problem might reproduce if using purge with another program).
I don't even know why would this affect ssh connection.
Could it be that google cloud is somehow using destination python for the ssh web?
In any case, if you are experiencing this problem try to avoid uninstalling anything from the base VM.
I have restarted our google cloud compute engine instance, however after the restart ssh is no longer working and giving connection refused.
I have verified and the ssh keys are configured for the users, and firewall rules are open for ssh.
Is there any other method I can use to try and resolve this?
The first thing to do is to check the Serial console output of the machine to determine if the SSH daemon has started or not. That log can be accessed from the Developer Console.
If you couldn't ssh to the instance you can follow the below step to access the instance from the serial console:
Connect to the instance using the serial console
1. Go to the VM instances page in Google Cloud Platform console.
2. Click on the instance for which you want to add a startup script.
3. Click the Edit button at the top of the page.
4. Click on ‘Enable connecting to serial ports’
5. Under Custom metadata, click Add item.
6. Set 'Key' to 'startup-script' and set 'Value' to this script:
#! /bin/bash
useradd -G sudo USERNAME
echo 'USERNAME:PASSWORD' | chpasswd
7. Click Save and then click RESET on the top of the page. You might need to wait for some time for the instance to reboot.
8. Click on 'Connect to serial port' in the page.
9. In the new window, you might need to wait a bit and press on Enter of your keyboard once; then, you should see the login prompt.
10. Login using the USERNAME and PASSWORD you provided.
When I execute the command "iisreset" through an ssh terminal on a remote windows machine, I get the following error:
Attempting stop...
Restart attempt failed.
Access denied, you must be an administrator of the remote computer to use this
command. Either have your account added to the administrator local group of
the remote computer or to the domain administrator global group.
When I type whoami, it shows that I am the administrator. My cygwin ssh session is running as the "cyg_server" user who has admin privileges.
My ssh server is configured with privilege separation and allows me to login as administrator.
When I run the command locally, it works fine. The problem is execution through ssh.
I've also used process monitor to see what's going on, but it does not indicate the problem.
That is pretty strange because I am able to do admin-only operations in remote ssh such as:
echo "hi">/cygdrive/c/x.txt
rm /cygdrive/c/x.txt
Turning off UAC did not make a difference.
Any ideas?
I had a similar problem: unable to start/stop services using net start/net stop from a remote password-less (public/private key) SSH user. Attempting to start/stop the service was resulting in a "System Error 5 has occurred. Access is denied." error).
I had to install Cygwin's LSA authentication package (see http://cygwin.com/cygwin-ug-net/ntsec.html#ntsec-setuid-overview) in order for (I presume) setuid to work properly for password-less logins.
The problem should go away once LSA is installed on the Cygwin/SSH host and the machine has been rebooted.
I got scared of the LSA package mentioned in #user3609241's answer because of this sentence in the LSA docs:
as soon as the LSA encounters serious problems (for instance, one of
the protected LSA processes died), it triggers a system reboot.
But, those same docs point to a very easy way to "runas" SYSTEM - just use the at command:
$ date
Mon, Jan 12, 2015 8:17:35 PM
$ at 20:18 iisreset
Added a new job with job ID = 1
$ at
Status ID Day Time Command Line
-------------------------------------------------------------------------------
1 Today 8:18 PM iisreset
It works, at the cost of having to wait up to 59 seconds.
(wrapping the above sequence of commands in a simple-to-call script is left as an exercise to the reader; our management util is written in Perl so it was pretty straightforward).
Run the Cygwin terminal as administrator
I am using some EC2 instances to run some large jobs I can not run locally. The issue I am seeing is that after a while (X hours since the process started) my connection on my shell gives me a broken pipe error
ubuntu#ip-10-122-xxx-xxx:~/stratto/ode$ Write failed: Broken pipe
The instance is still there because I can reconnect with no problems, but how can I reconnect and get back at seeing the logs of the process as before the 'Broken Pipe'
Any tip much appreciated,
Thanks!
Redirect your output to a file and then run the program "nohup ..." to ensure the disconnect doesn't kill it. Use "tail -f" to monitor the redirected file.
Note: Originally said to use "tee" but that won't work. I think a straight redirect and then tail on the file works.
You can use screen to run processes in the cloud even when you are not connected to the server.
sudo apt install screen
To specifically address the issue described in the original post (e.g. connecting to AWS EC2 instances) I a basic example and a more advanced example of using screen.
You can use "screen". Detach from it and ping to google.com. So there ssh session will be active through out the installation.