DEA-1TT5 Virtualization and Cloud Storage 2 — Questions and Answers
Question 1: What is the difference between IaaS, PaaS, and SaaS in cloud computing?
- They are three different cloud pricing models
- IaaS provides infrastructure (compute/storage/network), PaaS provides a development platform, SaaS provides ready-to-use applications — each at a higher level of abstraction (Correct answer)
- IaaS is for private clouds, PaaS for hybrid, SaaS for public clouds
- They refer to network, compute, and storage layers respectively
Correct answer: IaaS provides infrastructure (compute/storage/network), PaaS provides a development platform, SaaS provides ready-to-use applications — each at a higher level of abstraction
IaaS (Infrastructure as a Service) offers raw compute/storage/networking resources; PaaS (Platform as a Service) adds a managed development environment; SaaS (Software as a Service) delivers complete applications — each abstracts more of the infrastructure.
Question 2: What is a 'hybrid cloud' storage architecture?
- A cloud environment that uses both Linux and Windows servers
- An architecture that integrates on-premises private cloud/data center infrastructure with public cloud services, allowing data and applications to move between them (Correct answer)
- A multi-vendor cloud strategy using only public cloud providers
- A cloud environment optimized for hybrid workloads mixing VMs and containers
Correct answer: An architecture that integrates on-premises private cloud/data center infrastructure with public cloud services, allowing data and applications to move between them
Hybrid cloud combines on-premises infrastructure with one or more public clouds, enabling organizations to keep sensitive data on-premises while bursting to the cloud for scalability or archiving cold data to reduce cost.
Question 3: What is 'cloud tiering' in storage systems?
- Organizing cloud providers by cost tiers for procurement decisions
- Automatically moving infrequently accessed data from on-premises storage to lower-cost cloud storage while keeping active data local (Correct answer)
- Creating multiple copies of data across different cloud regions
- Tiering cloud storage by access speed within a single cloud provider
Correct answer: Automatically moving infrequently accessed data from on-premises storage to lower-cost cloud storage while keeping active data local
Cloud tiering extends on-premises storage by automatically migrating cold data to cloud object storage, reducing the on-premises storage footprint while making the data still accessible through the local storage interface.
Question 4: In virtualization, what is 'thick provisioning' versus 'thin provisioning' for VM disk files?
- Thick provisioning allocates the full virtual disk size on datastore creation; thin provisioning allocates space dynamically as data is written (Correct answer)
- Thick provisioning uses compressed disk files; thin provisioning uses uncompressed
- Thick provisioning creates read-only disk templates; thin provisioning creates writable disks
- Thick provisioning is used for SSDs; thin provisioning for HDDs
Correct answer: Thick provisioning allocates the full virtual disk size on datastore creation; thin provisioning allocates space dynamically as data is written
Thick-provisioned VMDKs reserve all requested disk space immediately on the datastore, preventing overcommitment; thin-provisioned VMDKs allocate space on demand, enabling higher VM density at the risk of running out of datastore space.
Question 5: What is 'software-defined storage' (SDS)?
- Storage that is defined using JSON configuration files
- A storage architecture that decouples storage software from the underlying hardware, enabling storage services to run on commodity hardware and be managed by policy (Correct answer)
- Storage managed exclusively through a software dashboard without hardware
- An all-flash storage array with embedded management software
Correct answer: A storage architecture that decouples storage software from the underlying hardware, enabling storage services to run on commodity hardware and be managed by policy
SDS separates storage control and management software from the hardware, allowing storage services (replication, deduplication, snapshots) to run on commodity servers, improving flexibility and reducing vendor lock-in.
Question 6: What is VMware vSAN and how does it create storage?
- A software-defined SAN that aggregates local server drives into a shared storage cluster accessible to all cluster hosts (Correct answer)
- A SAN management interface built into vCenter
- A network protocol for connecting VMs to external SAN arrays
- A backup solution for VMware environments
Correct answer: A software-defined SAN that aggregates local server drives into a shared storage cluster accessible to all cluster hosts
VMware vSAN pools the local flash and HDD drives installed in ESXi cluster hosts to create a shared, distributed storage datastore, eliminating the need for external SAN or NAS hardware.
DEA-1TT5 Virtualization and Cloud Storage 2
What is the difference between IaaS, PaaS, and SaaS in cloud computing?