Module 04 - Virtualized Data Center - Storage

Question 1

Process of masking the underlying complexity of physical storage resources and presenting the logical view of these resources to compute systems.

Answer 1

Storage Virtualization

(4.4)

Question 2

Benefits of Storage Virtualization

Answer 2

1) Adds or removes storage without any downtime, 2)Increases storage utilization, reducing TCO, 3) Provides non-disruptive data migration between storage devices, 4) Supports heterogeneous, multi-vendor storage platforms, 5) Simplifies storage management
(4. 5)

Question 3

Example of storage virtualization at the compute layer

Answer 3

Storage provisioning for VMs

(4.6)

Question 4

Examples of storage virtualization at the network layer

Answer 4

Block-level virtualizationFile-level virtualization

(4.6)

Question 5

Examples of storage virtualization at the storage layer

Answer 5

Virtual provisioningAutomated storage tiering

(4.6)

Question 6

How are VMs stored?

Answer 6

As a set of files on storage space available to the hypervisor

(4.8)

Question 7

How does a virtual disk appear to a VM?

Answer 7

As a local physical disk drive. The hypervisor may access a FC storage device, IP storage devices such as iSCSI, and NAS devices

(4.8)

Question 8

Two file systems used by the hypervisor to manage the VM files

Answer 8

1) Virtual Machine File System (VMFS) - the hypervisor’s native file system, 2) Network File System (NFS) such as NAS file system
(4. 9)

Question 9

Characteristics of VMFS

Answer 9

1) Cluster File System, 2) can be access by multiple compute systems simultaneously, 3) Provides on-disk locking
(4. 10)

Question 10

What are methods to expand a VMFS

Answer 10

1) Expand VMFS dynamically on the volume partition on which it is located, 2) Add one or more LUNs to the source VMFS volume.
(4. 11)

Question 11

Enables VM to directly access LUNs in a storage system.

Answer 11

Raw Device Mapping (RDM)

(4.12)

Question 12

When is Raw Device Mapping (RDM) useful?

Answer 12

When an application running on the VMs are required to know the physical characteristics of the storage device.

(4.12)

Question 13

Benefits of Raw Device Mapping

Answer 13

1) Good when huge volume of data on LUN is not practical to maintain on a virtual disk, 2) Enables clustering the VM with the physical machine
(4. 12)

Question 14

The ______ protocol is ussed by the hypervisor to access NAS file system.

Answer 14

NFS

(4.13)

Question 15

True or False: Hypervisors come with NFS client software for NFS server (NAS) access.

Answer 15

True

(4.13)

Question 16

______ volumes are created on a NAS device, provide storage to VM and are accessed by multiple compute systems simultaneously.

Answer 16

NFS

(4.13)

Question 17

Embeds storage virtualization intelligence at the network layer.

Answer 17

Network-based virtualization

(4.15)

Question 18

How network-based storage virtualization is applied

Answer 18

1) Block-level (SAN), 2) File-level (NAS)
(4. 15)

Question 19

Creates an abstraction layer at the SAN, between physical storage resources and volumes presented to compute.

Answer 19

Block-level Storage Virtualization

(4.16)

Question 20

True or False: Block-level storage virtualization enables the combination of several LUNs from one or more arrays into a single virtual volume before presenting it to the compute system.

Answer 20

True

(4.16)

Question 21

Encapsulates physical storage devices and applies layers of logical abstraction to present virtual volumes to compute layer.

Answer 21

Storage Virtualization Appliance

(4.17)

Question 22

Mechanisms used by a virtualization appliance to divide storage volumes. May be all or part of the underlying storage volume. (EMC-specific term)

Answer 22

Extents

(4.17)

Question 23

Enables clients to access files using logical names which are independent of the actual physical location.Maps logical path of a file to the physical path names.Simplifies access to files: clients no longer need to have multiple mount points to access data located on different NAS devices.

Answer 23

File-Level Storage Virtualization - Global Namespace

(4.18)

Question 24

Provides an abstraction layer in the NAS / File servers environment.

Answer 24

File-level Storage Virtualization

(4.18)

Question 25

Ability to present a LUN to a compute system with MORE capacity than what is physically allocated to the LUN.

Answer 25

Virtual Provisioning (Thin Provisioning)

(4.21)

Question 26

Virtual Storage Provisioning can be implemented at what layers?

Answer 26

1) Storage Layer, 2) Compute Layer
(4. 21)

Question 27

Basic benefit of virtual provisioning

Answer 27

Better storage capacity utilization

(4.21)

Question 28

Logical device where the physical storage need not be completely allocated at time of creation.

Answer 28

Thin LUN

(4.23)

Question 29

Minimum amount of physical storage allocated at a time to a Thin LUN from a Thin Pool

Answer 29

Thin LUN Extent

(4.23)

Question 30

Collection of physical drives that provide physical storage allocated to the Thin LUN.

Answer 30

Thin Pool

(4.23)

Question 31

How is a Thin Pool created?

Answer 31

By specifying a set of drives and a RAID type for that pool.Thin LUNs are then created out of that pool (similar to traditional LUN created on a RAID group).

(4.24)

Question 32

Balances the used capacity of physical disk drives over the entire pool when new disk drives are added.Restripes data across all disk drives.

Answer 32

Thin Pool Rebalancing

(4.25)

Question 33

How is virtual provisioning done at the compute level?

Answer 33

Hypervisor performs virtual provisioning to create virtual disks for VMs.

(4.26)

Question 34

Two types of virtual disks offered by the hypervisor.

Answer 34

1) Thick disk 2)Thin disk
(4. 26)

Question 35

Virtual Provisioning Benefits

Answer 35

1) Reduces administrative overhead.2) Improves capacity utilization.3) Reduces cost.4) Reduces downtime.
(4. 27)

Question 36

Virtual Provisioning Best Practices

Answer 36

1) Drives in Thin pool should have the same RPM. 2) Drives in the Thin pool should be of the same size. 3) Provision Thin LUNs for applications that can tolerate some variation in performance.
(4. 28)

Question 37

Establishing a hierarchy of storage type, and identifying the candidate data to relocate to the appropriate storage type to meet service level requirements at minimal cost.

Answer 37

Storage Tiering

(4.29)

Question 38

Automates the storage tiering process.Enables the non-disruptive data movement between tiers.Improves application performance at the same cost or provides the same performance at a lower cost.Configures data movement within a storage array (intra-array) or between storage arrays (inter-array).

Answer 38

Automated Storage Tiering

(4.30)

Question 39

Automates the storage tiering process within an array.Enables efficient use of SSDs and SATA drive technologies.Performs data movements between tiers at sub-LUN level.Employs cache tiering to improve application performance further.

Answer 39

Intra-Array Automated Storage Tiering

(4.31)

Question 40

Enables a LUN to be broken down into smaller segments and tiered at that level. Different levels have different performance characteristics.

Answer 40

Sub-LUN Tiering

(4.32)

Question 41

True or False: Movement of data with much finer granularity (e.g., 8MB) greatly enhances the value proposition of automated storage tiering.

Answer 41

True

(4.32)

Question 42

Three major building blocks of automated storage tiering

Answer 42

1) Storage Type, 2)Storage Groups, 3)Policies
(4. 33)

Question 43

Creates a large capacity secondary cache using SSDs. Enables tiering between DRAM cache and SSD drives (secondary cache).Most reads are now served directly from high performance tiered cache.

Answer 43

Cache Tiering

(4.34)

Question 44

Automates the identification of active or inactive data to relocate them to different performance / capacity tiers between the arrays.

Answer 44

Inter-Array Automated Storage Tiering

(4.35)

Question 45

EMC product that provides local, metro and Geo unified storage access.

Answer 45

EMC VPLEX

(4.37)

Question 46

EMC Product that provides automated storage tiering for Thin pools. Supports data movement at sub-LUN level. Moves data based on user-defined policies and application performance needs. Data movement is automatic and non-disruptive.

Answer 46

EMC Symmetrix VMAX - FAST VP

(4.38)