libvirt xml: host starting with image in remote server - http

I am trying to launch a guest vm on an ubuntu host, from a remote machine. The image for the guest is also at the remote machine(http server as image repo).
The following is the domain xml segment for disk section:
<disk type='network' device='disk'>
<driver name='qemu' type="qcow2"/>
<source protocol="http" name="img/guest_1.qcow2">
<host name="192.168.10.16" port="80"/>
</source>
<target dev='vdb' bus='virtio'/>
</disk>
While i am launching the vm i get this error:
virsh -c qemu://hostname/system start guest_vm
error: Failed to start domain guest_vm
error: internal error: process exited while connecting to monitor: 2017-04-07T12:31:24.421836Z qemu-system-x86_64: -drive file=http://192.168.10.16:80/img/guest_1.qcow2,format=qcow2,if=none,id=drive-virtio-disk1: curl block device does not support writes
Any inputs on how to resolve the issue?
From domain xml related documents, i could see other protocols like rbd,nbd,iscsi,etc being used.Is it not possible with http ?

As the error message says, the curl driver in QEMU (which is used for accessing disks via the http,https & ftp network protocols) only supports read-only access. You've configured a disk which requires read-write access, hence it reports an error.
Even if curl did support writes you really wouldn't want to use it. The HTTP protocol is not an efficient way to access guest disks. You should use any of iSCSI, NBD, NFS, RBD or GlusterFS instead.

Related

web GRPC and Iroha (JS implementation for iroha)

I am trying to run this docker file https://gitlab.com/snippets/1713665
consoles
I have running iroha container as you can see in right console on 50051 port, but on running the above docker file for web GRPC then you can see in left console it is unable to make connection. as i have also tried with enabling and disabling the firewalls and also with opening the 50051 withudo ufw allow 50051 sudo ufw allow 50051 ...But in the end i have the same results
"Err: connection error: desc = "transport: Error while dialing dial tcp 127.0.0.1:50051: connect: connection refused". Reconnecting... system=system"
I have also posted this issue month ago but no once gave me any response, Thats why i am reposting with further elaboration
Try running the grpc web proxy, with the backend address as localhost, instead of whatever is default in the gitlab post.
ex. ./grpcwebproxy-v0.13.0-osx-x86_64 --backend_addr=localhost:50051 --run_tls_server=false
From the console logs, it looks like it is trying to connect to dev.localdomain:50051

Mosquitto: Starting in local only mode

I have a virtual machine that is supposed to be the host, which can receive and send data. The first picture is the error that I'm getting on my main machine (from which I'm trying to send data from). The second picture is the mosquitto log on my virtual machine. Also I'm using the default config, which as far as I know can't cause these problems, at least from what I have seen from other examples. I have very little understanding on how all of this works, so any help is appreciated.
What I have tried on the host machine:
Disabling Windows defender
Adding firewall rules for "mosquitto.exe"
Installing mosquitto on a linux machine
Starting with the release of Mosquitto version 2.0.0 (you are running v2.0.2) the default config will only bind to localhost as a move to a more secure default posture.
If you want to be able to access the broker from other machines you will need to explicitly edit the config files to either add a new listener that binds to the external IP address (or 0.0.0.0) or add a bind entry for the default listener.
By default it will also only allow anonymous connections (without username/password) from localhost, to allow anonymous from remote add:
allow_anonymous true
More details can be found in the 2.0 release notes here
You have to run with
mosquitto -c mosquitto.conf
mosquitto.conf, which exists in the folder same with execution file exists (C:\Program Files\mosquitto etc.), have to include following line.
listener 1883 ip_address_of_the_machine(192.168.1.1 etc.)
By default, the Mosquitto broker will only accept connections from clients on the local machine (the server hosting the broker).
Therefore, a custom configuration needs to be used with your instance of Mosquitto in order to accept connections from remote clients.
On your Windows machine, run a text editor as administrator and paste the following text:
listener 1883
allow_anonymous true
This creates a listener on port 1883 and allows anonymous connections. By default the number of connections is infinite. Save the file to "C:\Program Files\Mosquitto" using a file name with the ".conf" extension such as "your_conf_file.conf".
Open a terminal window and navigate to the mosquitto directory. Run the following command:
mosquitto -v -c your_conf_file.conf
where
-c : specify the broker config file.
-v : verbose mode - enable all logging types. This overrides
any logging options given in the config file.
I found I had to add, not only bind_address ip_address but also had to set allow_anonymous true before devices could connect successfully to MQTT. Of course I understand that a better option would be to set user and password on each device. But that's a next step after everything actually works in the minimum configuration.
For those who use mosquitto with homebrew on Mac.
Adding these two lines to /opt/homebrew/Cellar/mosquitto/2.0.15/etc/mosquitto/mosquitto.conf fixed my issue.
allow_anonymous true
listener 1883
you can run it with the included 'no-auth' config file like so:
mosquitto -c /mosquitto-no-auth.conf
I had the same problem while running it inside docker container (generated with docker-compose).
In docker-compose.yml file this is done with:
command: mosquitto -c /mosquitto-no-auth.conf

MPI A process or daemon was unable to complete a TCP connection

Open MPI: 4.0.1a
HostFile:
34bb0519eAAA
a2935f150BBB
I am in machine 34bb0519eAAA. And I could use ssh a2935f150BBB to connect a2935f150BBB successfully. And also ssh 34bb0519eAAA In machine a2935f150BBB to connect 34bb0519eAAA successfully .
But when I mpiexec command . I get error message
****Warning: Permanently added '[XX.XX.XX.XX]:XX' (a2935f150BBB'IP address) to the list of known hosts.**
----------------------**--------------------------------------
A process or daemon was unable to complete a TCP connection
to another process:
Local host: a2935f150BBB
Remote host: 34bb0519eAAA
This is usually caused by a firewall on the remote host. Please
check that any firewall (e.g., iptables) has been disabled and
ORTE was unable to reliably start one or more daemons.
This usually is caused by:
* not finding the required libraries and/or binaries on
one or more nodes. Please check your PATH and LD_LIBRARY_PATH
settings, or configure OMPI with --enable-orterun-prefix-by-default
* lack of authority to execute on one or more specified nodes.
Please verify your allocation and authorities.
* the inability to write startup files into /tmp (--tmpdir/orte_tmpdir_base).
Please check with your sys admin to determine the correct location to use.
* compilation of the orted with dynamic libraries when static are required
(e.g., on Cray). Please check your configure cmd line and consider using
one of the contrib/platform definitions for your system type.
* an inability to create a connection back to mpirun due to a
lack of common network interfaces and/or no route found between
them. Please check network connectivity (including firewalls
and network routing requirements).
I am very confused that.Because I run ssh to each other successfully . How could fail that.
Here is ssh connection
ssh a2935f150BBB
Warning: Permanently added '[XX.XX.XX.XX]:XX to the list of known hosts.
Welcome to Ubuntu 18.04.1 LTS (XXXXXXXXXXXXXXXXXX)
Documentation: https://help.ubuntu.com
Management: https://landscape.canonical.com
Support: https://ubuntu.com/advantage
This system has been minimized by removing packages and content that are
not required on a system that users do not log into.
To restore this content, you can run the 'unminimize' command.
Last login:XXXXXXXXXXXXX from XXXXXXXXXX

mount.nfs: requested NFS version or transport protocol is not supported

NFS Mount is not working in my RHEL 7 AWS instance.
When I do a
mount -o nfsvers=3 10.10.11.10:/ndvp2 /root/mountme2/
I get the error:
mount.nfs: requested NFS version or transport protocol is not supported
Can anyone point me where I am wrong?
Thanks.
Check the nfs service is started or reboot the nfs service.
sudo systemctl status nfs-kernel-server
In my case this package was not running and the issue was in /etc/exports file where i was having same IP address for two machines.
So i commented one ip address for the machine and restarted nf-kernel-server using
sudo systemctl restart nfs-kernel-server and reload the machine.
It worked.
A precision which might be useful for the dump (like me): systemctl status nfs-server.service and systemctl start nfs-server.service must be executed on the server!
Some additional data
If, like me, you've deleted a VM without shutting it down right you might also need to manually edit the file /etc/exports because NFS is trying to connect to it and fails but doesn't continue with the next, it just dies.
After that you can manually restart as mentioned in other answers.
In my case, a simple reload didn't suffice. I had to perform a full restart:
sudo systemctl status nfs-kernel-server
In my case, it didn't work correctly with version NFS 4.1.
So in Vargantfile in each place where is type: 'nfs' I added coma and nfs_version: 4, nfs_udp: false
Here is more detailing explanation NFS
If you're giving a specific protocol to connect with, also check to make sure your NFS server has that protocol enabled.
I got this error when trying to start up a Vagrant box, and my nfs server was running. It turns out that the command Vagrant uses is:
mount -o vers=3,udp,rw,actimeo=1 192.168.56.1:/dir/on/host /vagrant
Which specifically asks for UDP. My server was running but it was not configured to enable connecting over UDP. After consulting /etc/nfs.conf, I created /etc/nfs.conf.d/10-enable-udp.conf with the following contents to enable udp:
[nfsd]
udp=y
The name of the file doesn't matter, as long as it's in the conf.d directory and ends in .conf. Depending on your distribution it may be configured differently. You can directly edit nfs.conf, but using a conf.d file is more likely to preserve the changes after upgrading your system.
Try to ping IP address of the server "ping " from client "ping , if you get reply then install nfs server on the host. Then edit /etc/exports file don't forget to add port along with IP address
I got the solution: make an entry in nfs server /etc/nfsmount.conf with Defaultvers=3 .
There will # Defaultvers=3 just unhash it and then mount on nfs client.
Issue will be resolved!

JNDI over HTTP on JBoss 4.2.3GA

I've got a remote server on eapps.com that I'm using as my "production" server. I have my own computer at home that I'm using as my "development" server. I'm trying to use JNDI over HTTP to do some batch processing. The following works at home, but not on the eapps machine.
I'm connecting to some EJBs (stateless session), and have my jndi.properties set to this:
(this is for the eapps machine)
java.naming.factory.initial=org.jboss.naming.HttpNamingContextFactory
java.naming.provider.url=http://my.prodhost.com:8080/invoker/JNDIFactory
java.naming.factory.url.pkgs=org.jboss.naming.client:org.jnp.interfaces
# timeout is in milliseconds
jnp.timeout=15000
jnp.sotimeout=15000
jnp.maxRetries=3
(this is for my machine at home)
java.naming.factory.initial=org.jboss.naming.HttpNamingContextFactory
java.naming.provider.url=http://localhost:8080/invoker/JNDIFactory
java.naming.factory.url.pkgs=org.jnp.interfaces
java.naming.factory.url.pkgs=org.jboss.naming.client
# timeout is in milliseconds
jnp.timeout=15000
jnp.sotimeout=15000
jnp.maxRetries=3
As I said, it works at home, but when I try it remotely, I get:
Can not get connection to server. Problem establishing socket connection for InvokerLocator [socket://my.prodhost.com:4446//?dataType=invocation&enableTcpNoDelay=true&marshaller=org.jboss.invocation.unified.marshall.InvocationMarshaller&socketTimeout=600000&unmarshaller=org.jboss.invocation.unified.marshall.InvocationUnMarshaller]
...
Caused by: java.net.ConnectException: Connection timed out: connect
Am I doing something wrong here, or is it possibly a firewall issue? To the best of my knowledge, port 4446 is not blocked.
Are the differences in the jndi.properties intentional (at the java.naming.factory.url.pkgs property level)?
Also, can you run a netstat -a | grep 4446 on both machines and update the question with the output?
Update: If the netstat command didn't return anything for port 4446 (JBoss was running, right?), then the JBoss Remoting Connector for the UnifiedInvoker service is very likely not listening on your eApps host, hence the connection timeout. Maybe this service has been disabled by eApps, you should contact the support and discuss this with them.
Just in case, a sample Connector configuration can be found in the jboss-service.xml under the server node's conf directory. Maybe compare the remote one (if you have access to it) with your local file to confirm this (but if it's disable, there must be a reason, discuss it with the support).
And by the way, this is what I get when I run the netstat command with JBoss 4.2.3.GA started on my GNU/Linux machine (default configuration):
$ netstat -a | grep 4446
tcp 0 0 localhost:4446 *:* LISTEN

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