EBS Flashcards

Question

network jitter

Answer 1

a variance in latency, or the time delay between when a signal is transmitted and when it is received. This variance is measured in milliseconds (ms) and is described as the disruption in the normal sequence of sending data packets.

Answer 2

Bandwidth can be measured in bits per second (bps) megabits per second (Mbps) and gigabits per second (Gbps). Having a high bandwidth doesn’t guarantee high network performance. It is theoretical packet delivery, whereas throughput is practical If throughput in the network is being affected by network latency, packet loss, and jitter then your service will see delays even if you have a substantial amount of bandwidth available.

Answer 3

are incremental - only backup changed blocks they use I/O so don't run them while the app is handling a lot of traffic you don't have to detach a volume when doing a snapshot but it is recommended max 100000 snapshots per account

Answer 4

S3 but you won't see them directly, but you will get billed for S3 space

Answer 5

you can copy snapshots across AZ or regions

Answer 6

you can create AMI from snapshots

Answer 7

need to be pre-warmed - use fio or dd command to pre-read the entire volume

Answer 8

using Amazon Data Lifecycle Manager

Answer 9

1. snapshot the volume 2. optionally copy the volume to a different region 3. create a volume from the snapshot in the AZ of your choice

Answer 10

1. data at rest is encrypted inside the volume 2. all the data in flight moving between the instance and the volume is encrypted 3. all the snapshots are encrypted 4. all volumes created from snapshot are encrypted 5. when you copy an unencrypted snapshot, you can enable encryption AES-256

Answer 11

Encryption has a minimal impact on latency

Answer 12

1. create an EBS snapshot of the volume 2. encrypt the EBS snapshot (using copy) 3. create new EBS volume from the snapshot - the volume will also be encrypted 4. attach the encrypted volume to the original instance

Answer 13

megabit per second (symbol Mbit/s or Mb/s, often abbreviated "Mbps") is a unit of data transfer rate equal to: 1,000 kilobits per second 1,000,000 bits per second 125,000 bytes per second 125 kilobytes per second

Answer 14

kilobit per second (symbol kbit/s or kb/s, often abbreviated "kbps") is a unit of data transfer rate equal to: 1,000 bits per second 125 bytes per second

Answer 15

gigabit per second (symbol Gbit/s or Gb/s, often abbreviated "Gbps") is a unit of data transfer rate equal to: ``` 1,000 megabits per second 1,000,000 kilobits per second 1,000,000,000 bits per second 125,000,000 bytes per second 125 megabytes per second ```

Answer 16

terabit per second (symbol Tbit/s or Tb/s, sometimes abbreviated "Tbps") is a unit of data transfer rate equal to: ``` 1,000 gigabits per second 1,000,000 megabits per second 1,000,000,000 kilobits per second 1,000,000,000,000 bits per second 125,000,000,000 bytes per second 125 gigabytes per second ```

Answer 17

terabit per second (symbol Tbit/s or Tb/s, sometimes abbreviated "Tbps") is a unit of data transfer rate equal to: ``` 1,000 gigabits per second 1,000,000 megabits per second 1,000,000,000 kilobits per second 1,000,000,000,000 bits per second 125,000,000,000 bytes per second 125 gigabytes per second ```

Answer 18

kilobyte per second (kB/s) (can be abbreviated as kBps) is a unit of data transfer rate equal to: 8,000 bits per second 1,000 bytes per second 8 kilobits per second

Answer 19

megabyte per second (MB/s) (can be abbreviated as MBps) is a unit of data transfer rate equal to: 8,000,000 bits per second 1,000,000 bytes per second 1,000 kilobytes per second 8 megabits per second

Answer 20

gigabyte per second (GB/s) (can be abbreviated as GBps) is a unit of data transfer rate equal to: ``` 8,000,000,000 bits per second 1,000,000,000 bytes per second 1,000,000 kilobytes per second 1,000 megabytes per second 8 gigabits per second ```

Answer 21

terabyte per second (TB/s) (can be abbreviated as TBps) is a unit of data transfer rate equal to: ``` 8,000,000,000,000 bits per second 1,000,000,000,000 bytes per second 1,000,000,000 kilobytes per second 1,000,000 megabytes per second 1,000 gigabytes per second 8 terabits per second ```

Answer 22

mebibit per second 1 mebibit = 220 bits = 1048576bits = 1024 kibibits[3] This unit is most useful for measuring RAM and ROM chip capacity. The mebibit is closely related to the megabit which equals 106 bits = 1,000,000 bits. 1 megabit = 106bits = 1000000bits = 1000 kilobits.

Answer 23

mebibyte per second mebibyte is equal to 1048576bytes, i.e., 1024 kibibytes. The unit symbol for the mebibyte is MiB. 1024 MiB = 1 gibibyte (GiB)

Answer 24

some instances do not come with Root EBS volume Instead, they come with Instance Store = ephemeral storage it is physically attached to the machine where your EC2 is block storage like EBS some instance types have it attached. Root is still EBS volume but there is also extra storage called ephemeral0

Answer 25

1. Better I/O performance (no network involved) very high IOPS, hundreds of thousands of IOPS - EBS cannot achieve this (64000 IOPS is max) 2. good for buffer / cache / scratch data / temporary content 3. data survives reboots

Answer 26

1. on stop or termination instance store is lost 2. you can't resize it on the fly or add new stores to EC2 once you've provisione an instance store 3. backups must be operated by the user 4. risk of data loss if hardware fails so replicate the data across other ISs in other stores

Answer 27

disks up to 7.5 TiB tebibytes for the moment can be stripped to reach 30 TiB but once you set up a disk in local instance store, it cannot change its size

Answer 28

tebibyte 1 tebibyte = 240 bytes = 1099511627776bytes = 1024 gibibytes 1024 TiB = 1 pebibyte (PiB)

Answer 29

Redundant Array of Independent drives Raid is just a collection of disks in a pool to become a logical volume.

Answer 30

RAID0 sharing data randomly to multiple disk. This won’t have full data in a single disk. If we use 3 disks half of our data will be in each disks.

Answer 31

used in RAID 1 Mirroring is making a copy of same data. In RAID 1 it will save the same content to the other disk too.

Answer 32

it is automatically replicated across multiple servers in an Availability Zone to prevent the loss of data from the failure of any single component. This replication makes Amazon EBS volumes ten times more reliable than typical commodity disk drives.

Answer 33

if you want to increase performance, for ex., IOPS to 100000 EC2 instance will have one logical volume (RAID0 Stripe) backed by two or more EBS volumes. The data will go to either of them.

Answer 34

if you want to mirror your EBS volumes to increase fault tolerance EC2 instance will have one logical volume (RAID0 Stripe) backed by two or more EBS volumes. The data will go to both of them

Answer 35

is possible as long as the OS supports it (Windows, Linux). It is not something you configure in AWS console, rather on the OS level in EC2 instance RAID5, RAID6 and RAID10 are not recommended

Answer 36

if one disk fails, the total logical volume is gone, all the data is failed increased risk to have faults

Answer 37

you get more total disk space and IO, increase in performance

Answer 38

1. an application that needs a lot of IOPS and doesn't need fault tolerance 2. a database that has replication already built-in

Answer 39

we have to send the data to 2 EBS volumes at the same time, so we have to use 2 times the network throughput you need an EC2 instance that has more network throughput to handle writing to several EBS volumes at a time

Answer 40

When fault tolerance is more important than I/O performance; for example, as in a critical application.

Answer 41

get terminated by default if the EC2 instance gets terminated you can disable it

Answer 42

increase EBS volume size because EBS IOPS peaks at 16,000 IOPS. or equivalent 5334 GB. You can 1. mount EBS volumes in RAID0 2. change to an IO1

Answer 43

mount an EFS

Answer 44

Instance Store provides the best disk performance

Answer 45

It is possible to run a database on EC2. It is also possible to use instance store, but there are some considerations to have. The data will be lost if the instance is stopped, but it can be restarted without problems. One can also set up a replication mechanism on another EC2 instance with instance store to have a standby copy. One can also have back-up mechanisms. It's all up to how you want to set up your architecture to validate your requirements. In this case, it's around IOPS, and we build an architecture of replication and back up around it you can't use - EBS GP2 drive because its max is 16000 IOPS - EBS IO1 - max is 64000