Storage and Backup

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Storage and Backup

• Chapter 16

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Areas of Discussion

• Managing the Data
• Disk Storage Technology
• Tape Storage and Backup
• Information Lifecycle Management
• Additional Resources

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George Carlin

• . . . All you need in life is a little place for
  your stuff . . .

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Information

• Heart of information is data
• Entire field is Information Technology
• Exponential rate of the amount of data growth

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Managing the Data

• Data retention
• User education
• Shared data storage
• Quotas

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Managing the Data continued

• Data retention establish data-retention
  policies
  
• Age of data analysis
• How long should the files of a user that has left
  the company be kept?
  
• How long should backup tapes be kept?
• What happens to files in shared areas of the
  network?
  

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Managing the Data continued

• Remember
• Users owners of data
• IT custodian of data
• While all sales data may look the same to you,
  all hardware looks the same to them.

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Managing the Data continued

• User Education
• Network is the place to backup rather than on
  local desktops.
  
• Travelers can store on network as well as on
  laptop.
  
• Avoid saving large files from e-mails due to huge
  space requirements
  
• Users can use CD or DVD as backup options rather
  than workstations.
  

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Managing the Data continued

• Storage space grows
• Backup procedures grow
• Recovery procedures take longer to complete

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Managing the Data continued

• Items that frequently need to be removed
• Temporary files
• Copies of software installation images
• Games
• Music
• Personal photos and videos
• Backups of workstations

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Managing the Data continued

• Shared Data Storage
• Requests should be made to IT
• Identify which users can access a certain area of
  shared storage
  
• Request identifies who is responsible for
  managing that shared storage
  
• The days of limitless access and almost limitless
  disk space are over.

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Managing the Data continued

• Quotas
• A users mailbox
• A network directory
• The total amount of space available to an
  individual user in all locations

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Disk Storage Technology

• Disk drives are the nuts and bolts of data
  storage.
  
• Direct Attached Storage
• DAS is part of the server
• Considered an inefficient use of hardware due to
  the investment made in the server, and its
  capacity often goes under-utilized.

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Disk Storage Technology continued

• Network attached storage
• NAS combines traditional disk array technology
  with intelligence. Intelligence comes from a
  processor and small operating system, embedded in
  the NAS unit. (could be considered a server)
• The entire unit is optimized for storage and ease
  of use.
  
• Can take right out of box and use with very small
  amount of configuration.

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Disk Storage Technology continued

• Based on file-level access rather than
  block-level access on storage area networks.
  
• Storage Area Network
• SAN block-level access
• Server issues a request for specific blocks of
  data from the disks method block storage
  
• Fibre channel network vs. TCP/IP and Ethernet

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Disk Storage Technology continued

• Just a bunch of disks (JBOD)
• Lower level storage solutions vs. SAN and NAS
• Some say JBOD is synonymous with DAS
• Others say JBOD is unprotected storage (no RAID
  or mirror-imaging)

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Disk Storage Technology continued

• Storage Network Connectivity (Fibre Channel and
  iSCSI)
  
• Fibre Channel SAN environments have used Fibre
  Channel (FC) for connectivity
  
• Provides gigabit speeds and most common
  connection method for SANs.
  
• Can be implemented on copper cabling as well as
  fiber-optic cables.

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Disk Storage Technology continued

• FC is considerably faster and often used as an
  alternative to SCSI for connecting servers with
  storage devices.
  
• Requires specialized hardware FC host-bus
  adapter (HBA) to allow it to connect to an FC
  switch (traditional network switch)
  
• Combination of FC cabling, HBAs, and switches is
  commonly referred to as the Fibre Channel, or
  SAN, Fabric.
  

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Disk Storage Technology continued

• Can provide speeds of 2 Gbps
• Variation is Fibre Channel over IP (FCIP)
• iSCSI
• Overcomes many limitations of traditional Small
  Computer Systems Interface (SCSI)
  
• Distance limitations
• Number of devices
• Allows you an almost limitless numbers of devices
  and extends the geography dramatically
  essentially to any device on the LAN or WAN
  

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Disk Storage Technology continued

• Can use existing Ethernet infrastructure for your
  SAN solution
  
• Trade off Provides half speed of FC technology
• Disk drive types
• ATA (also known as IDE) most used type of drive
  in desktop and laptops, uses 16-bit parallel
  interface, supports transfer rates 133 MB/sec.
  

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Disk Storage Technology continued

• Serial ATA (SATA) transfer rates of 150MB/sec
• Future iterations of transfer rates will be 300
  and 600 MB/sec.
  
• These devices draw less power and are easier to
  install.

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Disk Storage Technology continued

• SCSI latest is SCSI Ultra/320)
• Transfer rate 320 MB/sec
• SCSI environment consists of a controller and a
  cable, with all the disk drives connected to the
  same cable.
  
• Common to have multiple controllers and multiple
  cables to ensure redundancy and eliminate single
  points of failure.
  

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Disk Storage Technology continued

• Factors that Impact Disk Drive Performance
• Rotation speed range 5,400 to 15,000 rpm
• The higher the speed, the more often data is in
  the right place to be read
  
• Average access time
• Average time to position the heads so data can be
  read
  
• Cache size
• The bigger the better
• Internal transfer rate
• Speed that data can be transferred within the
  drive

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Disk Storage Technology continued

• Redundant array of inexpensive/independent disks
  (RAID)
  
• Defines different levels of protection with
  tradeoffs of performance and costs
  
• Table 16.1 page 441

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Tape Storage and Backup

• Preferred method for backup solutions
• Pros
• Inexpensive
• Transportable
• Cons
• Much slower than disk
• Sequential medium
• More fragile medium than disk and susceptible to
  deterioration over time
  

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Tape Storage and Backup

• Tape and Tape-Drive technologies
• Table 16.3 on p. 444

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Tape Storage and Backup

• Variations on Backup
• Disk-to-disk-to-tape
• Tape is slow medium so first backup goes to disk
  as a snapshot, and second backup is from that
  disk to tape
  
• Benefits
• Disk-to-disk backup is fast so impact to
  production environment is minimized
  
• Performance hit to production environment is also
  reduced

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Tape Storage and Backup

• Backup of the snapshot image happens faster since
  cont competing with any other processes or users
  for performance
  
• If user needs file from snapshot, it can be
  retrieved quickly
  
• Disadvantage
• Cost of the device that holds the snapshot image

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Tape Storage and Backup

• Disk-to-Disk
• Factors of consideration in eliminating tape
• Disk may be prohibitively expensive
• Isnt portable and could impact flexibility of
  disaster recover plans
  
• Live and backup at same location so may have
  backup sent across WAN. Cost of sufficient
  bandwidth could be expensive
  
• Restores across Wan may take significant amounts
  of time
  

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Tape Storage and Backup

• Data Encryption
• Decru and Neoscale Systems are two companies that
  offer solutions for encrypting a backup
  
• A Key up to 256-bits in length is commonly used
• Must store key so can decrypt backup tapes
• Dedicated network
• Performs faster
• Eliminates any impact it may have on users and
  production environment.

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Tape Storage and Backup

• Backup Schedule
• Full captures everything
• Differential captures only files changed since
  last full backup
  
• Incremental captures only files changed since
  backup of any kind.

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Tape Storage and Backup

• Backup Storage
• Store tapes offsite
• When to take offsite and return to onsite
• Two copies of backup tapesone onsite and one
  offsite

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Information Lifecycle Management

• ILM reflects the fact that the value and use of
  data information change over time.
  
• Age data files that havent been modified in
  some time
  
• Static data files that generally dont change

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Information Lifecycle Management

• With ILM an organization has to define different
  use classes of data critical, static, archival,
  transactional and needs of data over time
  (high-speed access, real-time replication)
• Once items have been defined, backup storage
  solutions can be determined.
  
• IT can then easily manage data and seamlessly
  migrate it to different storage solutions during
  the datas lifetime.

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Information Lifecycle Management

• ILM versus Hierarchical Storage Management (HSM)
• Both have common elements in data movement to
  storage forms
  
• Key difference HSM primarily relies on the
  measure of access frequency and/or age to
  determine when a file should be moved

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Information Lifecycle Management

• HSM is primarily one-directional (primary to
  secondary and secondary to tertiary)
  
• ILM move data based on a number of policies (in
  addition to age and access frequency) and to/from
  any storage solutions.
  

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Summary Slide

• Managing the Data
• Disk Storage Technology
• Tape Storage and Backup
• Information Lifecycle Management