Which one of the following statements incorrectly describes the characteristics of the CloudStack architecture?

1. Network environments such as basic zones, advanced zones, and VPCs are constructed to meet the requirements of a user.
2. System VMs automatically deploy when needed and collaborate with the management server to provide features required by the cloud environment.
3. Components such as hypervisor management, storage management, network management, authentication, and the Web user interface are independent services. Therefore, only the desired components can be selected and used.
4. It is possible to create a cloud environment in which different hypervisors are implemented under a single management server.

Answer

Answer: C

The CloudStack architecture provides a monolithic solution that concentrates most service-related functions (e.g., management and authentication of architecture components and the Web user interface) in the management server. Additional functions are performed by separate components called system VMs. Such VMs include secondary storage VMs, console proxy VMs, and virtual routers. These VMs are also controlled by the management server and are automatically deployed and reconfigured in response to user operations or according to load conditions.

In the CloudStack, it is possible to create a cloud environment in which different hypervisors are implemented under a single management server. However, the hypervisors in a cluster must be of the same type. In addition, Hyper-V must be implemented in its own separate zone.

The CloudStack supports multiple network architectures by default. In creating a zone, select either a basic zone or an advanced zone. Basic zones are flat networks in which all virtual machines are connected to the same network segment. Isolation between virtual machines is provided at layer-3 using the security group feature. With advanced zones, isolation is typically provided at layer-2 using VLANs, with a separate VLAN assigned to each account.

Virtual machines communicate with external devices and networks via virtual routers created automatically by the CloudStack. Normally, a single virtual router only supports a single virtual network. However, using a VPC, it is possible to connect multiple virtual networks to a single virtual router and to perform routing between virtual networks and control access using ACLs.

When KVM is used as a hypervisor, which of the following methods can be used to connect with primary storage?

1. NFS
2. CIFS
3. iSCSI
4. Fibre Channel

Answer

Answer: A, C, D

The CloudStack defines two types of storage: primary and secondary. Primary storage constitutes an area mounted on a host and stores virtual machines’ operating systems and virtual disks. Secondary storage stores virtual machines’ snapshots and templates.

The methods used to connect a hypervisor with primary storage differ depending on the hypervisor. When KVM is used as a hypervisor, it can use NFS, iSCSI, or Fibre Channel to connect with primary storage. When Hyper-V is used as a hypervisor, it can use CIFS to connect with primary storage.

Of the port numbers used for communication between the CloudStack management server and system VM, to which port number does the CloudStack management server listen?

1. 8250
2. 3922
3. 8080
4. 443

Answer

Answer: A

TCP port number 8250 is used for communication between the CloudStack management server and system VM. The CloudStack management server listens to port 8250. Thus, the correct answer is A.

sshd on the system VM listens to port number 3922 to enable logging into the system VMs from XenServer hosts and KVM hosts using SSH key authentication. Port number 8080 is the default port for accessing the CloudStack Web user interface, and port number 443 is used when, for example, accessing APIs using HTTPS.

When the CloudStack was installed, the script shown below was executed. Which one of the following statements incorrectly describes the executed script and its arguments?

# cloudstack-setup-databases cloud@1.2.3.4 --deploy-as=root:nonsense

1. The password for the user "cloud," with which the CloudStack accesses the database, is "nonsense."
2. The user "cloud" is created by the user "root."
3. The IP address of the database server is "1.2.3.4."
4. If the script completes normally, "Successfully initialized the database." is displayed.

Answer

Answer: A

The "cloudstack-setup-databases" script is used during management server installation to initialize the database and specify the username and password that the management server uses to connect to the database.

# cloudstack-setup-databases <clouduser>:<dbpassword>@<dbhost> --deploy-as=<user>:<password>

Options available for this command are as follows.
clouduser: username that the management server uses to connect to the database
dbpassword: password assigned to a user that the management server uses to connect to the database (optional)
dbhost: host name or IP address of the database server
user: username employed during database setup to connect to the database (optional)
password: password of the user employed during database setup to connect to the database (optional)

During the execution of the script presented in the above question, the database server "1.2.3.4" is accessed by the user "root" (with the password "nonsense"), and "cloud" (with no password) is created as a CloudStack user.

Which one of the following is not a virtual machine state?

1. Waiting
2. Stopping
3. Destroyed
4. Expunging

Answer

Answer: A

CloudStack virtual machines have the states as follows.
1.　Starting
2.　Running
3.　Stopping
4.　Stopped
5.　Destroyed
6.　Expunging

Which one of the following is an operation that can be performed by a domain administrator using the Web interface?

1. Creating a subdomain
2. Changing the number of resources to allocate to a subdomain
3. Allocating an exclusive host to an account
4. Adding an LDAP account

Answer

Answer: B

There are three types of CloudStack accounts: root administrator, domain administrator, and user.

A domain administrator is an account that has privileges to control resources within its domains. It can create new accounts within its domain and change the number of resources to allocate to a subdomain; it cannot change the number of resources allocated to its own domain. Administrator privileges for a higher level domain are required to change the number of resources in a domain. In addition, only a root administrator of a domain can create subdomains.

You would like to have a compute offering to be used only by a particular account. For this purpose, which one of the following configuration procedures is necessary?

1. Specify the account when creating the compute offering.
2. Specify a domain when creating the compute offering, and place the account in that domain.
3. After creating the compute offering, edit the compute offering to specify the account.
4. After creating the compute offering, edit the compute offering to specify the domain, and place the account in that domain.

Answer

Answer: B

A compute offering is a type of service offering and constitutes configuration information that specifies resources to allocate to a virtual machine. A compute offering can only be created by a root administrator. A user can select a compute offering that he/she would like from those created in advance by a root administrator and assign it to a virtual machine. When creating a compute offering, the number of CPU cores, clock frequency (MHz), and memory (MB) must be specified.

In addition, "Public" is an optional setting of a compute offering. When this setting is enabled (i.e., when its check box is checked) in creating a compute offering, the resulting compute offering will be available to all accounts. If this setting is disabled (i.e., if its check box is unchecked), "Domain” is displayed as an additional setting, and only accounts that belong to the specified domain can use the offering.

The only settings that can be changed once a compute offering is created are "Name" and "Description;"" thus, it is advisable to ensure that the settings are correct at the time of creation.

Which of the following statements correctly describe the monitoring feature of the virtual router (excluding VPC routers)? Select two options.

1. The monitoring feature detects when the HAProxy process implementing the load balancing function goes down and automatically restores it.
2. The monitoring feature can send alerts to the management server.
3. The monitoring feature can manage traffic information by retrieving the MIB using SNMP.
4. The monitoring feature supports network monitoring using sFlow.

Answer

Answer: A, B

CloudStack virtual routers are equipped with a monitoring tool. When particular services and processes terminate, they are automatically recovered. The virtual router currently provides services as follows (these services are not supported when using a VPC).

• DNS
• HA Proxy
• SSH
• Apache Web Server

Virtual routers are equipped with VRRP to increase redundancy. During a switch-over, an alert is sent to the management server, displayed in the CloudStack Web interface, and recorded in the management server log file. The virtual router’s MIB is not supported; thus, traffic information cannot be collected using SNMP. In addition, network monitoring using sFlow is not supported.

Which one of the following statements incorrectly describes the CloudStack API?

1. When sending an API request, an API key and secret key are used for account authentication.
2. HTTP GET and POST are used for API requests.
3. The format of API responses can be set to XML, JSON, or CSV.
4. Programming languages such as Java and PHP can be used to generate API requests.

Answer

Answer: C

The CloudStack provides a REST API; thus, HTTP GET and POST are used for API requests. In sending an API request, an API key and secret key must be used to authenticate the account. For API responses, the XML and JSON formats are supported, and the CSV format is not supported. Java, PHP, or other programming languages can be used to generate API requests. In addition, a convenient command-line tool that wraps the API, "CloudStack cloudmonkey CLI," has been implemented in Python and is available.