Transcript redundancy - UTRGV Faculty Web

REDUNDANCY
Dr. John P. Abraham
Professor
UTPA
This slide series is a summary of what
we discussed in class.
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Power
Broadband
Hard Drive
Backup
Cluster
Power Supply Redundancy
• Power Source
– AC
– Generator
– Solar
AC
• Problem with spikes and browns
• Should not have other appliances or devices
connected to it.
• Should have a direct circuit breaker
• Use surge protection for the whole circuit.
• I looked up Square D surge protector as an
example.
• Such outlets should be color coded (Orange or
Red)
Generator
• Should maintain it properly. Must start it each
week
• Need to have a transfer switch. There is a
time delay. Meanwhile your computer will go
off.
Solar with Battery back up
• Need to have pure sine wave inverters to be
used with electronic equipment.
• You can connect these batteries to the UPS
• Solar Array needs to have a voltage controller,
to keep it from over charging the batteries.
• Also needs to have a transfer switch.
• You can also use APC Redundant Automatic
Transfer switch or similar ones
UPS
• A must for all servers
• Check the voltage and wattage rating
• VA stands for voltage Amp – How much load a
UPS can handle at any given time. This will
tell you how many devices can be plugged in.
UPS software
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APC powerchute software
Powercom
Powershield
Notifies the server of the remaining power
Notifies administrator through text or email
Sends message to clients
Closes files and shuts down
Broadband redundancy
• Determine highest speed you would need and
that should become your primary broadband.
• Determine the lowest speed you can get by
without damaging your business much, make
that your secondary broadband.
• Both services should provided you with pool of
public IP addresses.
• Assign one of those IP addresses to appropriate
router or modem. In case of a modem the public
IP should be passed on or bridged to the load
balancer discussed below.
Redundancy and load balancer
• Purchase a router that is capable of load
balancing.
• All Private LAN traffic should go through this
router.
• A load balancer will have more than one WAN
port. Assign appropriate public IPs to each of
the WAN. Appropriate means the IP address
should come from the appropriate service
connected to the WAN port.
Stand by WAN service
• If the primary fails then the secondary should
take over
Load balancing
• If either the download speed or the upload
speed is similar you may want to load balance.
• Set appropriate policies for load balancing.
For example, you may want to set a policy for
secure connections to go through a
designated WAN.
RAID
• We discussed different levels of RAIDs and
advantage and disadvantage of each.
• Get hot pluggable hard drives, that way you
won’t have to bring the system down.
• RAID in itself does not assure you protection
against corruption.
• Must use backup along with RAID
Redundant Array of Inexpensive
Servers
• RAIS stripes and mirrors application code and
memory across an array of ordinary servers using
the standard RAID schemata of level 0, level 1,
level 5, level 1+0. This is possible through the
invention of a radical new memory management
system called Versioned Memory.
• However, I want to start with the old fashioned
way of achieving redundancy.
Backups
• Backup must on removable media, either tape
drive or removable hard drive.
• Discussed full and incremental backups
• Discussed rotation schedule. Must have a
removable media for each day, and for each
week. The weekly must go to fire proof vault.
• Remote backups
• Cloud backup – consider financial investment
Cluster