learnquest learning library content€¦ · ibm spectrum scale (formerly general-purpose file...

© Copyright IBM Corporation 2012 1

Unit three talks about storage.

Unit 3: Overview of storage components

LearnQuest Learning Library Content


Review your objectives for this unit.




This unit is about storages in a cloud environment. Depending on the compatibility with the computing hosts in the cloud, storages can vary from small disk drives to large storage enclosure systems. Although cloud users might not be able to request for particular type of storage, they get what they pay for. The use of storages in the cloud is bound to the quality of services the cloud service provider offers.

The location of storages decides the type of connection with computing hosts. A host might have limited number of disks internally. But, cloud storages are usually located external in storage systems that do not associate with a single host.

Reference:

IBM System Storage Solutions Handbook, Redbooks publication

http://www.redbooks.ibm.com/abstracts/sg245250.html?Open



In the cloud, you have many choices for storages that the cloud service provider offers. The visual shows an overview of IBM storage products. As a service consumer, you choose the product that fits your applications. The innovation factors on the left help improve storage services in the cloud. You might not see the bare metal storage products in the middle. However, different software products, on the right, help managing storages in the back of the cloud. This type of providing and renting services forces you to focus on the needs of the application instead of worrying what type of storage you should buy.





Your first requirement for storage comes when you create or deploy a VM. The diagram illustrates that a VM is made up of multiple file systems or volumes. Each one might come from different sources of storages. Most important is the boot volume from the virtual image for creating the base OS and kernel. Extra software packages for middleware or applications can be added from the software repository. Further customizations for the VM include separate user or application volumes. A VM also has the option of mounting or attaching data volumes from external storages.



From a cloud service interface, users might not see the options to choose internal or external storage for their VMs. However, the VM that you request might require the ability of shrinking or extending its storage size for example. That puts the VM storage volumes onto external storages. As a cloud service provider, you get much more flexibility with external storage. For example, the VM can be moved (VM migration and mobility) to any hosts that connect to the storage.

With external storage, you can also provide cloud services for storages independent of VM services. For example, users need storage in the cloud to store their photo or image files.




The pyramid illustrates different levels of cloud storage services. Similar to virtualization in computing resources in the cloud, storages are virtualization resources. You need only to install and work with “bare metal” storage systems when setting up your private cloud environment. With that in mind, storage virtualization works well in the cloud.




From a simplified point of view, storage virtualization works similarly to server virtualization. Hypervisor is a firmware or software component that sits on top of bare metal storage with the main tasks of allocating storage volumes. The storage virtualization software takes the volumes and makes them available in the form of virtualization resources that is used in the cloud.




Software defined storage (SDS) is a concept for standardizing storage virtualization in the cloud. Storage management software that implements SDS provides storage accesses independent of storage hardware. Common application programming interfaces cover operations across different cloud or virtualization environments.




Cloud is a multiple of nodes or multiple VMs environment. Most of the cloud operations such as moving a VM from one host to another or dynamically adding more VMs depend on a network or distribute file system.

The Network file system (NFS) is an example. When you have a cluster of VMs, users want to be able to access their data on any of the VMs. Such file systems can be mounted on all or some of the VMs that are called the NFS clients. The actual file system resides on a server. As a result, the file system performance is depending heavily on the server, which handles all the file system requests.




IBM Spectrum Scale (formerly General-purpose file system or GPFS in short) is a file system that is used in high performance computing. Comparing to NFS, Spectrum Scale implements the Network shared disk (NSD) protocol for distributing network-based block I/O among servers. By distributing storage data to the NSD servers, more application nodes can access data at a higher speed as comparing to direct access to storage.




The visual shows the four attributes of the Hadoop distributed file system (HDFS) that a cloud environment is depending upon. The attributes also summarize the values of servicing storage in the cloud.

What is Hadoop?

http://www-01.ibm.com/software/data/infosphere/hadoop/




Why virtualized storage? You see the possibility of transforming hardware storages into virtual resources is almost endless. The amount of live streaming or accumulated data is increasing every second. Data takes many formats and occupies huge storage spaces. If your data is permanent or needs to be saved regardless of for how long, it has to be moved through virtual storages to its destination. The datacenter is now the cloud.





Keywords - make sure you understand.




Write your answers here:

1.

2.

3.

4.




Answers are:

1. True

2. d - all the above

3. False

4. b - elastic

If you got all four correct - good job! If not take 25% off for each incorrect response. Go back and review if needed.




This lab covers three things - please review the slide.




Review the objectives.



learnquest learning library content€¦ · ibm spectrum scale (formerly general-purpose file...

Documents