Cybrary - CompTIA Cloud+

Network and direct storage types

• Network Attached Storage (NAS)
• Storage Area Network (SAN)
• Direct Attached Network (DAN)

Network Attached Storage (NAS)
     - Cheaper than SAN
     - lowest performance
     - attached to file server and network
     - current infrastructure

Storage Area Network (SAN)

     - access over the LAN
     - technician needs some kind of knowledge on installing and maintenance
     - vendor specific hardware and software
     - highest performance
     - block level allocation
     - configuration setting up time is higher than others

Direct Attached Network (DAN)
    - Directly attached to the local PCs

Protocols used

• IDE

• SATA

• SACI

Access and Protocol

Ethernet
     - typically RJ45 (8 pins) are used
     - Most commonly used protocol
     - cheap and easy to implement
     - require a wiring scheme

Fiber Channel (FC)

     - Uses for WANs
     - Fiber channels are used for connecting storage and servers

Topologies

• Point-To-Point

• Arbitrated loop

• Switched fabric

Internet Protocol (IP)

     - Internet layer in TCP/IP model 
     - provide traffic routing
     - dotted decimal(IPv4) notation or hexadecimal(IPv6)

Internet Small Computer System Interface (ISCSI) 
     - sends packets via SCSI commands through Ip networks

Fiber Channel Protocol

over fiber channel
SCSI commands
utilizes hardware to transmit packets
protocol offload engines (POE)

Fiber Channel Over Ethernet (FCOE)

Ethernet is used instead of Fiber
Transmit SCSI commands
cheaper than fiber
10Gbps Ethernet is used

Storage preparation and accessing

• Network shares

          resources available across the LAN
          local machines are used as drives
          ex:- NFS protocol with linux

• multipathing

          fault tolerance
           used NICs HBAs

• Logical unit numbers (LUNs)

         used as unique identifiers
         virtual hard disk from a block of allocated storage with in a  NAS or SAN
          devices which makes request informations are known as "Initiators"
          devices which perform the request known as "target"

• Zoning and LUN masking

           Zoining is isolating single server to a group of storage devices or a single storage device and it is done in hardware level

            LUN masking is making available to some hosts and unavailable for others

Disk types and configurations

Removable types

DIsks
Floppy
USB drive

Interface types

ATA - Advance Technology Attachement

     - particular ports
     - PATA - Parallel ATA

IDE - Integrated Drive Electronics
     computer chip which can be accesses by the hardware

Serial ATA
     faster, SATA1 SATA 2 SATA 3

Serial Attached SCSI (SAS)

Small Computer System Interface (SCSI)

Access Speed

Hard Disk Speed
Latence
Access time

Solid State Drive (SSD)

No moving parts
High performance storage devices


USB Drive

plug and play
temporary transfer and storage

Tape

device to read magnetic tape
slow seek time
used for off site storage

Tiering

Performance level of each tier

Tier 1 - mission critical
Tier 2 - major business applications
Tier 3 - financial data
Tier 4 - stores emails or data for log periods


Policies

Fitting data each tier policy to migrate between tiers
service agreement

RAID

RAID 1 - stripped
RAID 2 - mirror

RAID 0 + 1
RAID 1 + 0
 RAID  5 - block level stripped with distributed
RAID 6  - block level stripping with distributed parity and an additional parity block


UNIX file system

hierachical file system
top level is called root


NTFS (New Technology File System)

by microsoft
supports compression
volume shadow copy service (VSS)
Encrypting file system
Quotes

FAT (file Allocation Table)

legacy file system
used primary by removable media
doesnt support fetures for permission or encryption