Posts Tagged ‘cloud’

resolved – IOError: [Errno 2] No such file or directory when creating VMs on Oracle VM Server

August 25th, 2014 Comments off

Today when I tried to add one OVS server to Oracle VM Server server pool, there was error message like below:

Start - /OVS/running_pool/vm_test
PowerOn Failed : Result - failed:<Exception: return=>failed:<Exception: failed:<IOError: [Errno 2] No such file or directory: '/var/ovs/mount/85255944BDF24F62831E1C6E7101CF7A/running_pool/vm_test/vm.cfg'>

I log on one OVS server and found the path was there. And later I logged on all OVS servers in that server pool and found one OVS server did not have storage repo. So I removed that OVS server from pool and tried to added it back to pool and want to create the VM again. But this time, the following error messages prompted when I tried to add OVS server back:

2014-08-21 02:52:52.962 WARNING failed:errcode=50006, errmsg=Do 'clusterm_init_root_sr' on servers ('testhost1') failed.
File "/opt/ovs-agent-2.3/", line 651, in _cluster_setup
File "/opt/ovs-agent-2.3/", line 340, in _check
raise OVSException(error=ret["error"])

2014-08-21 02:52:52.962 NOTIFICATION Failed setup cluster for agent 2.2.0...
2014-08-21 02:52:52.963 ERROR Cluster Setup when adding server
2014-08-21 02:52:52.970 ERROR [Server Pool Management][Server Pool][test_pool]:During adding servers ([testhost1]) to server pool (test_pool), Cluster setup failed: (OVM-1011 OVM Manager communication with host_master for operation HA Setup for Oracle VM Agent 2.2.0 failed:
errcode=50006, errmsg=Do 'clusterm_init_root_sr' on servers ('testhost1') failed.

From here, I realized that this error was caused by storage repo could not created on that OVS server testhost1. So I logged on testhost1 for a check. As the storage repo was one NFS share, so I tried do a showmount -e <nfs server>, and found it's not working. And then I tried to check the tracert to <nfs server>, and it's not going through.

From another host, showmount -e <nfs server> worked. So the problem was on OVS server testhost1. After more debugging, I found that one NIC was on the host but not pingable. Later I had a check of the switch, and found the NIC was unplugged. I plugged in the NIC and tried again with adding back OVS server, creating VM, and all went smoothly.


Suppose you want to know the NFS clients which mount one share from the NFS server, then on any client that has access to the NFS server, do the following:

[root@centos-doxer ~]# showmount -a|grep to_be

-a or --all

List both the client hostname or IP address and mounted directory in host:dir format. This info should not be considered reliable.


If you met below error when trying to poweron VM:

2016-08-19 02:58:28.474 NOTIFICATION [PowerOn][testvm]: Start - /OVS/running_pool/testvm
2016-08-19 02:58:39.802 NOTIFICATION [PowerOn][testvm]: Result - failed:<error: (113, 'No route to host')>
File "/opt/ovs-agent-2.3/", line 168, in start_vm
raise e
2016-08-19 02:58:39.802 WARNING [PowerOn][testvm]: Result - failed:<error: (113, 'No route to host')>
File "/opt/ovs-agent-2.3/", line 168, in start_vm
raise e

Or below error when trying to import template:

Register an empty virtual machine

register the virtual machine genernal information

get the virtual machine detail information...

Invalid virtual machine type(HVM/PVM).

Then the cause should be the existence of problematic OVS server. You should check ocfs2.conf or remove maintenance OVS server then have a test.

vmware vsphere esx cloud computing terminology

June 25th, 2012 Comments off

Here's some terminologies related to vmware vsphere/esx:

Relationships Between the Component Layers of VMware vSphere

What is a datastore?

A datastore is a logical container that holds virtual machine files and other files necessary for virtual machine operations. Datastores can exist on different types of physical storage, including local storage, iSCSI, Fibre Channel SAN, or NFS. A datastore can be VMFS-based or NFS-based.

You can create a new datastore by formatting LUNs or by mounting NFS volumes to an existing host. In addition, you can add a host with existing datastores to the inventory.

What is a datacenter?

A datacenter is the primary container of inventory objects such as hosts and virtual machines. From the datacenter, you can add and organize inventory objects. Typically, you add hosts, folders, and clusters to a datacenter.

vCenter Server can contain multiple datacenters. Large companies might use multiple datacenters to represent organizational units in their enterprise.

Inventory objects can interact within datacenters, but interaction across datacenters is limited. For example, you can move a virtual machine with vMotion technology across hosts within a datacenter but not to a host in another datacenter.

 What is a Folder?

A folder is a container used to group objects and organize them into hierarchies. Folders provide a natural structure upon which to apply permissions.

The folder structure you see in the inventory varies depending on the inventory view.

 What is a host?

A host is a computer that uses virtualization software, such as ESX or ESXi, to run virtual machines. Hosts provide the CPU and memory resources that virtual machines use and give virtual machines access to storage and network connectivity.

What is a host profile?

A host profile captures the configuration of a specific host and allows you to duplicate the configuration to other hosts or clusters or to validate that a host's configuration meets datacenter needs. Host profilers help reduce manual steps in cluster host configuration.

You can attach and apply host profiles to hosts or clusters in this view or in the Hosts and Clusters view. When you perform host profile operations in the Hosts and Clusters view, you can right-click individual hosts or clusters in the inventory for some operations or use the Profile Compliance tab for cluster-level host profile operations when a cluster is selected.

What is a Template?

A template is a master image of a virtual machine that can be used to create new virtual machines. This image typically includes an operating system, applications, and configuration settings for the virtual machine.

Use templates to create virtual machines by deploying the template as a virtual machine. When complete, the new virtual machine is added to the folder that was selected when the template was deployed. You can use a template to create identical new virtual machines.

What is a Virtual Machine?

A virtual machine is a software computer that, like a physical computer, runs an operating system and applications. An operating system installed on a virtual machine is called a guest operating system.

Because every virtual machine is an isolated computing environment, you can use virtual machines as desktop or workstation environments, as testing environments, or to consolidate server applications.

In vCenter Server, virtual machines run on hosts or clusters. The same host can run many virtual machines.

What is a Resource Pool?

Resource pools can be used to hierarchically partition available CPU and memory resources of a standalone host or a cluster.

Creating multiple resource pools allows you to think more about aggregate computing capacity and less about individual hosts. In addition, you do not need to set resources on each virtual machine. Instead, you can control the aggregate allocation of resources to the set of virtual machines by changing settings on their enclosing resource pool.

What is a Cluster?

A cluster is a group of hosts. When you add a host to a cluster, the host's resources become part of the cluster's resources. The cluster manages the resources of all hosts within it.

Clusters enable the VMware High Availability(HA) and VMware Distributed Resource Scheduler(DRS) solutions.

What is the Hosts & Clusters view?

This view displays the set of computing resources that run on a particular host, cluster, or resource pool. Using the Hosts & Clusters view, you can manage and organize your inventory of computing resources.

What is the Virtual Machines & Templates View?

This view displays all virtual machines and templates in the inventory, arranged by datacenter. Through this view you can organize virtual machines into folder hierarchies.

What is the Datastores view?

This view displays all datastores in the inventory, arranged by datacenter. Through this view, you can organize datastores into folder hierarchies, manage existing datastores, and add and remove datastores to your inventory.

What is the Networks view?

This view displays the set of networking objects available on vCenter. Using the Networking view, you can create and manage networking with vNetwork Distributed Switches and view networking with Standard Switches configuration.

vSphere provides two types of network architecture. Networking with vNetwork Distributed Switches manages virtual machine and host networking at the datacenter level, while networking with Standard Switches manages virtual machine and host networking at the host level.

What is a Standard Switch network?

A network with Standard Switches is a network of virtual machines running on a single physical machine that are connected logically to each other so that they can send data to and receive data from each other. A network and its associated vSwitches provide the interface between virtual machine NICs and physical network adapters.

What is the Virtual Machine Port Group/VMkernel Port/Service Console port?

There are three types of network connections:

  1. Service console port – access to ESX Server management network
  2. VMkernel port – access to VMotion, iSCSI and/or NFS/NAS networks
  3. Virtual machine port group – access to VM networks

More than one connection type can exist on a single virtual switch, or each connection type can exist on its own virtual switch. For more information, you can refer to the following pdf file:

 What is the Host Profiles view?

The Host Profiles view is the management area of the vSphere Client for host profiles. This view allows administrators to create, edit, or delete host profiles.

You can attach and apply host profiles to hosts or clusters in this view or in the Hosts and Clusters view. When you perform host profile operations in the Hosts and Clusters view, you can right-click individual hosts or clusters in the inventory for some operations or use the Profile Compliance tab for cluster-level host profile operations when a cluster is selected.


More info here