The document provides an overview of various storage systems, including Directly Attached Storage (DAS), Network Attached Storage (NAS), Storage Area Networks (SAN), and cloud storage, highlighting their characteristics and use cases. It discusses trends such as the shift from personal data storage to enterprise storage needs, emphasizing data growth, redundancy, and management strategies in data centers. The presentation also addresses the future direction of storage solutions, including the potential rise of Data Center as a Service (DCaaS) and the integration of public cloud services.

1. Personal Storage to Enterprise
Storage System - A brief journey
through Storage Wonderland
Soumen Sarkar
co-founder, Idean

2. Goal and audience
 The presentation aims to provide a
bird’s eye view on digital storage
systems landscape at present
 It presents generic details and is not
intended to be any vendor-specific
 If you are looking for an overview of
storage-system in a data centre this
presentation could be useful to you
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3. Types of Storage Systems
 Directly Attached Storage
 Network Attached storage
 Storage Area Network
 Cloud storage - can be any combination of
above three but provides RESTful
interface
for storage access
3

4. Directly Attached Storage
(DAS)
L
A
N
S
e
r
v
e
r
• DAS - Storage box containing one or more hard
disks connected directly to the host or server
disks
• DAS ranges from simple hard disk attached to Enterprise DAS
your laptop to more complex enterprise-class server 4

5. Network Attached Storage (NAS)
File Access is
Users provided by
PC NFS [for unix]
or CIFS [for
windows]
protocol
LAN Server
for Data
Backup
Web
Server Mail NAS
Server DB Server
Server File
Server
Server [unix/windows]
network
• All users’ request served by the application servers and storage need
from application servers are provided by NAS box(es).
• Storage Capacity planning becomes simpler and centralized 5

6. Storage Area Network (SAN)
Users
• SAN provides
block storage
PC
to the
application
server
• Servers are
connected LAN
through SAN Web Mail DB File
switches (not
shown in
Server Server Serve Server
diagram) r
• Each Appl Disk
server has its
own Data
Array
organization Disk
/File System Array
• Each appl
server can plan
storage need Fibre-Channel / IP SAN
independently
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7. A simplified stack comparison for
DAS, NAS, SAN
DAS NAS SAN
Application Application Application
NFS, CIFS File System
Network
iSCSI, FC, FCoE
File System File System Network
RAID RAID RAID
SAT SAT SAT
A SAS FC A SAS FC A SAS FC
• In DAS, applications directly call File System calls for storage needs
• In NAS, applications [in different box] talk to NAS server over NFS or CIFS
protocols for all storage needs
• In SAN, applications behave like DAS but File System in the server access
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storage in disk-array over iSCSI, or FC protocol

8. SATA,SAS,FC Disk Drive - A
comparative view
SATA [Serial ATA] SAS [Serial FC [Fibre-
Attached SCSI] channel]
Performance Half-duplex, Full-duplex Full-duplex
1.5 GB/s introduced 3.0 GB /s 2.0 GB/s
3.0 GB/s in 2005 introduced, introduced
6.0 GB/s in 2007 4.0 GB in 2004
Connectivity 1 device 128 devices 127 devices
1 metre cable 6 metre cable 15 metre cable
SATA only SAS & SATA FC only
Redundancy Single-port HDD Dual-port HDD Dual-port HDD
Availability 8x5 duty cycle 24x7 duty cycle 24x7 duty cycle
6M hrs MTBF 12M hrs MTBF 12M hrs MTBF
Typical Cost Less than $1/GB $3-$4/GB $4-$5/GB
[see zdnet]
SATA is the cheapest, slowest and less reliable and FC is
costliest but is faster and is more reliable and is predominantly
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seen in SAN, SAS is relatively new but provides best of the

9. SCHEMATIC VIEW : A JOURNEY
FROM GIGABYTES OF PERSONAL
DATA TO PETABYTES OF
ENTERPRISE DATA
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10. Personal Storage System
Directly Public Cloud
Attached [Google Drive,
Storage Microsoft
(DAS) SkyDrive etc.]
• One’s personal data typically resides inside DAS and in public
cloud storage [ Gmail, Yahoo-mail, flickr, youtube, Google Drive,
SkyDrive, iTune]
• Data back up is taken in another standalone DAS
• Size ranges from few GB to few TB at present
• Further data growth will see movement of data to Cloud 10

11. Enterprise Data also is growing
fast
In the third quarter of 2012 (3Q12), total disk storage
systems capacity shipped reach 7,104 PetaBytes or 7
Exabytes, growing 24.4% year-over-year - IDC
Storage capacity growth projection: (V stands for
Virtualized) source
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12. Enterprise Storage: a schematic
view
DAS associated with Individual
PC/Laptop
Network attached Storage Area
Data Centre
Storage [NAS] Network [SAN]
Storage Backup Infrastructure
• Enterprise manages data in the order of PetaBytes and can have either NAS or SAN
or both
• Data growth, frequency of data access are important consideration for planning
storage infrastructure
• Data Replication [synchronous or asynchronous] and Data backup policy are two
major aspects of data centre strategy 12

13. Enterprise Storage II: Multiple Data
Centre helps faster disaster
recovery
DAS associated with DAS associated
Individual PC/Laptop with Individual
PC/Laptop
Network
Network Storage Storage
attache
attached Data Area Data Area
d
Storage Centre Network Centre Network
Storage
[NAS] [SAN] [SAN]
[NAS]
Storage Backup Storage Backup
Infrastructure Infrastructure
Site 1 Site 2
• Multi-site Data centre helps mitigate risk of single site failure
• Typically NAS of one site provides for standby NAS for the other site
• Site 1 and Site 2 are connected over FC or GigEthernet
• Data almost always gets synchronously replicated across sites
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14. An emerging trend
Infographics source
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15. Enterprise Storage System III:
connecting to Public Cloud
DAS associated with
Individual PC/Laptop
DAS associated with
Individual PC/Laptop
Public Cloud Storage
[Amazon EC3,
Network Storage Microsoft Azure,
Network Data
attached Storage
Area Rackspace]
attached
Storage Data Network
Centre Area
Storage
[NAS] Centre [SAN]
Network
[NAS] [SAN]
Storage Backup Infrastructure
Storage Backup Infrastructure
NAS gateway to SAN gateway to
Cloud Cloud
• To address rack-space limits in captive data centre enterprises often opt to move some data
to public cloud
• Cloud gateways like Nasuni /Twinstrata/Nirvanix/Ctera appliances connect enterprise NAS
or SAN seamlessly to Cloud
• They usually provide a RESTful API version for storage protocols like NFS, CIFS or iSCSI 15

16. Enterprise Storage System III-b:
connecting to Public Cloud
Securely
DAS associated
with Individual
DAS associated
PC/Laptop
with Individual Public Cloud
PC/Laptop Storage [Amazon
EC3, Microsoft
Network
Network Storage
Storage Azure, Rackspace]
attached Data
attache Area
Data
Storage Centre Network Area
d
[NAS] Centre[SAN]
Network
Storage
[SAN]
[NAS]
Storage Backup Infrastructure
SAN gateway to
NAS gateway Backup Infrastructure
Storage
to Cloud Cloud
Secure gateway to Cloud
• Storage infrastructure majorly deals with data in plaintext and that can be risk while dealing
with public cloud
• Using VPN only makes the communication channel between cloud and data centre secure
but does not protect the enterprise from intentional breach to data inside public cloud
• Secure gateway that encrypts data on the fly using AES 256 cryptography addressed the
need. One may use services like Ciphercloud or NetApp Datafort appliance to secure its data
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17. Extrapolating to Future: advent of
DCAS
 Many leading storage vendors are actively advocating for
something called ‘private cloud’
◦ A large part of that constitutes server and OS virtualization
◦ And storage virtualization i.e. logical provisioning of storage for the
servers
 However analysts predict this to be a transient phase and
eventually enterprises will move towards public clouds
[Gartner]
 DCAS or Data Centre As Service will be dominant service
model to be offered by the cloud vendors to enterprises
◦ Application Server, storage, security and retention of enterprise data will
be provided as a single solution
◦ With enterprise users already adopting public cloud for their private data,
So will only belikely scenariotheirfuture enterprise data centre
it the most consistent that for enterprise data also move to public
cloud
appear to be a combination of captive data centre and
DCAS. But Does that mean that future storage innovations
will be dominated by software? 17

18. It may be when we no longer know what to do, we have come
to our real work, and that when we no longer know which way
to go, we have begun our real journey.
- Wendell Berry
.. And the
journey
continues…
More storage commentary: Industry Bytes
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