Chapter 8 - Operational Elements

Question 1

What is crucial when it comes to power facility?

Answer 1

Redundancy

Question 2

What is a main problem with rural areas regarding power supply?

Answer 2

Most areas only have one supplier

Question 3

What should be considered when planning power line (Stromleitung) redundancy?

Answer 3

Place redundant cables on the opposite of the building

Question 4

What is meant by conditioning?

Answer 4

Adjusting electricity to suite system performance

Question 5

What are the Uptime Institute (UI) Tiers?

Answer 5

There are 4 tiers. Each level increases the costs & saftefy & features.

Tier 1: Power sicherstellen & Kühlungssystem

• Maintenance causes shutdown (as well as personnel activity)
• Annual maintenance needed to prevent outages and disruptions
• -> Often used for backups

Tier 2:

• Tier 1 but no downtime for maintenanec
• Untoward personnel MAY cause downtime
• Unplanned failues MAY cause downtime
• -> Good for SMEs to operate and maintain low oberhead

Tier 3:

• Tier 2 + multible distribution paths (dual power supllies)
• Unplanned loss of component MAY cause downtime
• Loss of single system CAUSES downtime
• -> Should serve all requirements

Tier 4 (Fault tolerant site infrastructure):

• Everything redundant and mostly now downtime and/or failure
• -> Serves especially high IP & large-scale

Question 6

What should be considered regarding administrators?

Answer 6

Should be isolated from customers to avoid interest conflict

Question 7

What should be considered regarding virtual machines/ instances?

Answer 7

They should be isolated. No VM should be aware of other VMs on the same host

Question 8

What types of clustered storages exist?

Answer 8

Tightly or loosely couled storages.

Tightly:
Tied to same physical backplane. Leads to drawbacks as all devices must be from the same vendbor but has enhanced performance as it scales.

Loosely:
Greater flexibility. Only logically connected.

Question 9

What is RAID and data dispersion and what is it used for?

Answer 9

Both used for data protection in a cloud storage cluster.
RAID (=redundant array of independent disks).
In RAID data is stored across all disks (striping) to recover data efficiently. Often partiy bits are added to the raw data to aid recovery.
Data dispersion: Data is sliced into chunks that are encrypted along with parity bits and then written along various drives in the cloud cluster.

Question 10

SAN vs. NAS

Answer 10

Storage Area Network vs Network attached storage.
SAN: Group of devices connected to the network that provide storage space to users. Storage is mounted to user’s machine. iSCSI or Fibre Channel Protocols used.
NAS: Network file server with drive (or group of drives) of which portions are assigned to users. TCP/IP used.

Question 11

What are KVMs

Answer 11

Keyboard, Video displays and mice.
They should be secured by e.g. secure data ports, labels, fixed firmware, soldered circuit board, reduced buffer, air-gapped pushbuttons

Question 12

What is the STRIDE model (in threat modeling)

Answer 12

Developed by Microsoft.
S= Spoofing (Obfuscate origin)
T= Tampering (Unauthorized mod. to data)
R = Repudiation (No proof for unauthorized actions)
I = Information Disclosure (Unauthorized access to information)
D = Denial of Serviec (Authorized entities have a loss of availability=
E = Escalation of privileges (Attacker gives himself more rights than he usually haves)