Express YourSelf !

storage system attributes: 

- availability [ # of replica , primary and secondary DB ]

the ability to access the data during failure conditions. The failures may be due to failures in the storage media, transport, controller or any other component in the system.

RTO Recovery Time Objective, MTTF, MTTR

- consistency

a. eventually consistent

b. strongly consistent

RPO Recovery Point Objective (time)

- scalability [ sharding = divide larger part into smaller part ]

a. number of client

b. throughput

c. capacity

d. increase number of component to support all above. 

- durability 

a. [ # of replica ]

b. endurance characteristic of storage media: SSD, spinning disk, tape

c. ability to detect corruption of data and recover corrupted data (bit-rot)

- performance 

a. latency

b. operation per second

c. throughput for read and throughput for write. 

For cloud native storage system : three more

- observability

- elasticity [ on demand scale up/down ] 

- data locality [ pod affinity ]

Storage stacks / layers

1. Data Access Interface [ block device, file system, App API: (Object store, k-v store and DB), PIP

2. Storage topology [ centralized, distributed, sharded, and hyper-converged ]

3. data protection layer, which adds redundancy [ RAID, Erasure coding, and Replicas ]

4. additional data services [ replication, snapshots (PiT Point in Time), clones, incremental snapshots for efficient backups ]

5. host, OS, physical non-volatile storage

Common Patterns and Features

1. Operator

2. CSI

2.1 CSI building blocks

2.1.1 identity gRPC service : info and capabilities of plugin

2.1.2 controller gRPC service: 

2.1.2.1. create and delete volume, 

2.1.2.2. create and delete snapshot, 

2.1.2.3. attach and detach volume, and 

2.1.2.4. expand volume

2.1.3. node gRPC service

2.1.3.1. mount and unmount volume, and 

2.1.3.1. expand volume.

2.2 CSI features

2.2.1 CSI topology and CSI capacity tracking provides input to K8s scheduler. 

2.2.2 raw block mode ( instead of file system)

2.2.3 snapshot and group snapshot for backup / recovery. 

3. K8s workload API

Volume Claim Template

4. Topology Aware Scheduling

5. Pod Disturption Budget

6. Resource Management

6.1 pod's [ guaranteed ] QoS, 

6.2 pod's [ higher than normal ] priority

6.3 VPA is better than HPA for statefulset. 

7. Separation of CP (using operator) and DP (E-W traffic)

8. Default secure

8.1 no port accessible outside

8.2 k8s secret. 

Day 2 operations

Upgrade

- CRD version

Backup/Restore

- App level

- volume level with hook so during backup, app does not use volume 

Increase / Decrease Storage capacity

- stateful set can expand storage volume

- HPA

Data Migration

- init containers

- job

Reference: 

• https://docs.google.com/document/u/0/d/1ro-M0aTBT64irBIy_n6Z-MkVubXc8ltBOiAJtXHw4oo/mobilebasic#h.dsrlcg44gbsz
• CNCF Storage Whitepaper version 2 https://docs.google.com/document/d/1Ag9PxdIe3iaMHcI5joHjyqo-x7fbIQErT02XkZz7Zvw/edit#heading=h.uvwp1nxx8pio 
• Data Protection workflows https://github.com/kubernetes/community/blob/master/wg-data-protection/data-protection-workflows-white-paper.md
• Cloud Native Disaster Recovery for Stateful Workloads https://bit.ly/cncf-cloud-native-DR
• Performance & Benchmarking  https://bit.ly/cncf-sig-storage-performance-benchmarking

1. We must have Monthly Budget

- We need to analyze our expenses to find out planned and unplanned expenses

2. We shall have Emergency Fund (9x to 12x monthly expenses)

It includes: 

- Term insurance

- health insurance

- Critical illness cover

- disability cover

Does it includes

- credit cards?

3. Do not ignore inflation. 

4. Power of compounding : SIP

5. Invest in equity and equity related product

- People invest in FD, Real estate, Gold

- Rich people do not invest in FD, Real estate and gold. 

- They become rich by their own business or other's business (equity) 

1991 to 2023

CAGR 19% 

BSE sensex 999 to 65000 points

- No for F&O

- No for intra-day

- We should have Goal Based investment. Without that, we get sub optimal return

A. Child's education

B. Dream vacation

C. Retirement plan

- What create wealth

A. income

B. savings

C. investment

We buy things we don't need. with money we don't have to impress people, that we do not like. 

6. New trend in abroad: Financial freedom and retire early. 

Funding retire is different. 

- must do

- no return

- For car/home all wants to provide load. No loan for retirement. 

How long saving will last after retirement? 

0 to 30 : student and early stage career. 

30 to 60 : accumulation and save

60 to 100 : distribution

Today Rs. 60,000 monthly expense

7% inflation

325646 after 25 years. 

We can try "retirement corpus building XLS"

The Yoga Sutras of Patañjali is a collection of Sanskrit sutras (aphorisms) on the theory and practice of yoga

It has four section. 

This blog post is on 2nd section. SAADHAN PAAD: and few initial SUTRA from 3rd section VIBHUTI PAADA: 

What is क्रिया-योग: ?

1. तपः, 

2. स्वाध्याय

3. ईश्वर-प्रणिधान

Why क्रिया-योग: ?

1. समाधि भावना

2. क्लेश तनू

What are क्लेश ?

1. अविद्या 

* Root cause of other 3

* Considering 

- अनित्य as नित्य 

- अशुचि as शुचि 

-  दुःख as सुख

- अनात्म as आत्म-ख्याति:

2. अस्मिता : दृक् दर्शन शक्त्यो: एकात्मता

3. राग : सुख अनुशयी Promises happiness

4. द्वेष  : दुःख अनुशयी

5. अभिनिवेश:

We shall get rid of क्लेश  by प्रतिप्रसव = चित्त को अपने कारण में विलीन करने के साधन 

We shall get rid of वृत्ति by ध्यान 

If root of क्लेश remains then we get

• 1. जाति - जन्म,
• 2. आयु: - आयु 
• 3. भोग: 

The Yoga Sutras of Patañjali is a collection of Sanskrit sutras (aphorisms) on the theory and practice of yoga

It has four section. 

This blog post is on 1st section. SAMAADHI PAAD: 

योग: चित्त  वृत्ति निरोधः ।

चित्त भूमि प्रकार:

• 1.क्षिप्त
• 2. विक्षिप्त
• 3. मूढ़
• 4.एकाग्र एवं
• 5. निरुद्ध

 All our habits , positive and negative are related to 

1. Process : It is like part of routine. OR it is due to RAJAS GUNA. OR some qualities like greed, laziness etc.

2. Outcome: It generates some visible, tangible/intangible  outcome. OR our desire for some result, tangible/intangible  outcome

3. Personality: some personal traits, beliefs, value, self concept, memory of some past incident. 

All habits have some root cause behind it. 

Motivation to change habit: 

- Autonomy : Some more power, authenticity, freedom

- Competence : skill

- Relatedness : How it benefits me. Having some better reason to quit the habit. 

We shall replace our habit with better habit.