Module 5: Block, File & Object Based Storage Systems (Object Based Storage System)

Question 1

What are the limitations of NAS?

Answer 1

cannot scale to extremely high capacity

data growth adds high overhead to NAS systems in terms of permissions and nested directories

file system requires more management the bigger they get

performance degrades as system grows - metadata capacity also limited as new apps introduced to environment

Question 2

What is an object in object based storage?

Answer 2

the fundamental unit of object based storage

support API integration + software defined infrastructure

Question 3

What is contained in an object?

Answer 3

user data - metadata - retention - access pattern

Question 4

What is object metadata used for?

Answer 4

optimize search
retention policies
automated deletion of objects

Question 5

How is an object identified?

Answer 5

unique Object ID - allows access without specifying storage location

Question 6

How is an object ID created?

Answer 6

applies specialized algorithms to the data

fingerprinting process that guarantees unique identification

Question 7

What happens if you change any part of the object data?

Answer 7

new Object ID made

Question 8

What is an object storage database?

Answer 8

used to track where objects and metadata are stored

uses Object IDs to access storage location records for retrieval

Question 9

How does an object storage device (OSD) store data?

Answer 9

uses flat address space so objects exist at the same level

objects can’t be placed inside of objects

Question 10

What does the flat address space storage system of an OSD allow?

Answer 10

no hierarchy of files or directories

billions of objects can be stored in single namespace

Question 11

How does a hierarchical file system store data?

Answer 11

organizes data in form of files/directories

limits number of files that can be stored

Question 12

What is an OSD controller?

Answer 12

server that runs the OSD OS and provides services to manage environment

Question 13

What are the three parts of an OSD system?

Answer 13

controllers
internal network
storage

Question 14

What are the two key functions of an OSD controller?

Answer 14

metadata services
storage services

Question 15

What are the metadata services for an OSD controller?

Answer 15

responsible for generation object IDs

maintains mapping of object IDs and file system namespace

sometimes metadata services runs inside application server

Question 16

What are the storage services for an OSD controller?

Answer 16

manages set of disk where data is stored

controller connects to storage via internal network

Question 17

What does the internal network in an OSD controller do?

Answer 17

provides inter-controller and controller to storage connection

Question 18

What does the application server do in an OSD environment?

Answer 18

accesses the controller to store or retrieve data over an external network

Question 19

What type of storage media is usually used to store object data?

Answer 19

low cost high density disk

Question 20

What are the key features of an OSD storage system?

Answer 20

scale out architecture
multitenancy
metadata driven policy
global namespace
flexible data access method
automated system management
data protection (Geo distribution)

Question 21

What are the benefits of the multi-tenancy capabilities of OSD?

Answer 21

allows multiple apps/clients to be served from same infrastructure

each app securely partitioned

data neither comingled or accessible by other tenants

Question 22

What are the benefits of the global namespace capabilities of OSD?

Answer 22

abstracts storage from apps and provides common view independent of location

unburdens client apps from need to keep track of where data is stored

Question 23

What are the flexible data access methods of OSD?

Answer 23

supports REST/SOAP APIs for mobile access and file protocols like CIFS/NFS

Question 24

What is the automated system management of an OSD?

Answer 24

provides self-healing and auto-configuring capabilities

redundant components means no single point of failure

Question 25

How is data protection implemented in an OSD?

Answer 25

replication and erasure coding

Question 26

What is an OSD gateway?

Answer 26

presents file and block based storage interfaces to apps

performs protocol conversion to send data directly to cloud storage

Question 27

What are the benefits of an OSD gateway?

Answer 27

encrypts data before transferring it to cloud

supports dedupe and compression

maintains local cache to reduce latency

provides data management layer to know which data to send to cloud

can be physical or virtual appliance that operates as software