2.5

Question 1

Redundancy

Answer 1

Duplication of parts of systems so org can continue to operate even with failures on a system

Question 2

Disk redundancy

Answer 2

Multipath IO creates other paths to ensure one failure doesn’t stop the data flow

Raid, may lose physical drives
there are parts across other drives

Raid 0 striping without parity, no backups
Raid 1 mirroring duplicates for fault tolerance but requires twice the disk space
Raid 5 striping with parity, fault tolerant only requires additional disk for redundancy

Question 3

Load balancing

Answer 3

Some servers are active some are on standby depending on traffic volume

Question 4

Nic teaming

Answer 4

Load balancing fail over

Using both active and standby connections to aggregate bandwidth

Multiple network adapters

Nics talk to each other mulicast and fails of Nic doesnt respond

Question 5

Power redundancy

Answer 5

Uninterrupted Power supply, has batteries that allow For temp outages

1offline/standby ups enable after power is loss
2. Line-interactive, based on voltage to balance to become optimal fillin in difference
3. Online/double conversion ups, always providing batter power no need to switch on or off

Or use generators using fuel

Question 6

Dual power supplies

Answer 6

Multiple Power supplies For multiple power sources where each can hadle
100% but distributes 50/50 if needed

Question 7

Power distribution unit

Answer 7

Multiple Power outlets a rack that connects to ethernet and has monitoring

Question 8

Replication

Answer 8

Frontend and dat seperate so many frontends can access one database, helps when one frontend fails

San storage area networks specialize in high performance network storage devices

Question 9

Backup types

Answer 9

File backups (archive bit) full back up, incremental (only files since last incremental back up), differential (all files changed since last full backup)

Question 10

Backup media

Answer 10

Magnetic tape (100gb to terabytes)
Disk back ups (faster than magnetic canduplicate and compress)
Copy back up image

Question 11

Nas vs sas

Answer 11

Network arrached storage, file level access need to change full file to fix
Storage area network, block level access, can change single portion

Question 12

Resiliency

Answer 12

Tearing down old instances and creating new

Non persistence, cloud app instances are constantly built and torn down, snapshots can be used to preserve the complete state of a device, making it possible to revert to various different snapshots

Question 13

High avaialbity

Answer 13

Redundancy doesn’t mean always available
High avaialbity is always on
But comes with higher
Costs

Question 14

Order of restoration

Answer 14

Needs to correct order To work,

Database first