STORAGE

Question 1

NAS VS SAN

Answer 1

Network attached storage
Storage area Network

One is storage attached and available to the network, like EFS

SAN- Multiple connected network devices that act as one once connected to vmware. almost like a cluster of storage. This is like EBS. Aws manages the infrastructure of the drives, clients will connect to them.

Question 2

Raid levels

Answer 2

0- Striping
1- mirror
5 striping with parity? need three or more
6 striping DOUBLE parity
10 striping and mirror, database server, strong tolerance

Question 3

parity and raid 5 /6

Answer 3

equivalent of entire disk is used to store parity
meaning: 4 TB storage can only store 3 tarabytes of data with a 4 disk setup.

parity bit, extra bit that denotes the nature of the bits before it, even/odd number of ones. use something like a checksum remainder to add the amount.

raid 6, two sets of parity data, parity has redundancy

Question 4

IOPS

Answer 4

input and output operations per second
RANDOM workload, nonsequential, usually small.

PATTERN: Random
Size: small data 4kb , extra large is 512kb
MIx: composition of read and write

Question 5

iops oltp

Answer 5

random pattern
8kb size
30 reads and 70 percent write

Question 6

database

Answer 6

sequential
64k
100% read

Question 7

video

Answer 7

512k
mix of read and write multiple streams
sequential

Question 8

throughput

Answer 8

IOPS*BLOCKSIZE

Question 9

latency

Answer 9

time to retrieve data or write data. want low latency response to data etc. , load times.