Tuesday, April 16, 2019

SMB/CIFS/SAMBA/NFS

SMB

So what is SMB? SMB stands for “Server Message Block.” It’s a file sharing protocol that was invented by IBM and has been around since the mid-eighties. Since it’s a protocol (an agreed upon way of communicating between systems) and not a particular software application, if you’re troubleshooting, you’re looking for the that is said to implement the SMB protocol.

The SMB protocol was designed to allow computers to read and write files to a remote host over a local area network (LAN). The directories on the remote hosts made available via SMB are called “shares.”

CIFS

CIFS stands for “Common Internet File System.” CIFS is a dialect of SMB. That is, CIFS is a particular implementation of the Server Message Block protocol, created by Microsoft.
CIFS vs SMB

Most people, when they use either SMB or CIFS, are talking about the same exact thing. The two are interchangeable not only in a discussion but also in application – i.e., a client speaking CIFS can talk to a server speaking SMB and vice versa. Why? Because CIFS is a form of SMB.

While they are the same top level protocol, there are still differences in implementation and performance tuning (hence the different names). Protocol implementations like CIFS vs SMB often handle things like file locking, performance over LAN/WAN, and mass modification of file differently.

CIFS vs SMB: Which One Should I Use?

In this day and age, you should always use the acronym SMB.

I know what you’re thinking – “but if they’re essentially the same thing, why should I always use SMB?”

Two reasons:-

1.) The CIFS implementation of SMB is rarely used these days. Under the covers, most modern storage systems no longer use CIFS, they use SMB 2 or SMB 3. In the Windows world, SMB 2 has been the standard as of Windows Vista (2006) and SMB 3 is part of Windows 8 and Windows Server 2012.

2.) CIFS has a negative connotation among pedants. SMB 2 and SMB 3 are massive upgrades over the CIFS dialect, and storage architects who are near and dear to file sharing protocols don’t appreciate the misnomer. It’s kind of like calling an executive assistant a secretary.

Samba and NFS

CIFS and SMB are far from the entirety of file sharing protocols and if you’re working to make legacy systems interoperate, it is quite likely that you’re also going to run into situations where others are necessary. Two other prominent file sharing protocols you should know about are Samba and NFS.
SAMBA
What is Samba? Samba is a collection of different applications with when used together let a Linux server perform network actions like file serving, authentication/authorization, name resolution and print services.

Like CIFS, Samba implements the SMB protocol which is what allows Windows clients to transparently access Linux directories, printers and files on a Samba server (just as if they were talking to a Windows server).

Crucially, Samba allows for a Linux server to act as a Domain Controller. By doing so, user credentials on the Windows domain can be used instead of needing to be recreated and then manually kept in sync on the Linux server.

NFS

The acronym NFS means “Network File System.” The NFS protocol was developed by Sun Microsystems and serves essentially the same purpose as SMB (i.e., to access files systems over a network as if they were local), but is entirely incompatible with CIFS/SMB. This means that NFS clients can’t speak directly to SMB servers.

So what does NFS mean in terms of your network communications toolkit? You should use NFS for dedicated Linux Client to Linux Server connections. For mixed Windows / Linux environments use Samba.

Wednesday, April 10, 2019

AWS CSAA - AWS Certified Solutions Architect Associate - 2019 - 4 Week Learning Path



Week 1:-

To get a good overview of basic concepts and architecture one should get started with the official Guide AWS Certified Solutions Architect Official Study Guide: Associate Exam. You can watch the videos from https://www.udemy.com/aws-architect/learn/ and  read the guide as both are synched and it will help go through the written material faster.

Week 2:-

Go through the Linux Academy and BackSpace Academy Videos as these cover a lot more detailed scenarios with labs. I particularly recommend "The Orion Papers" which i found to be very useful. The concepts are very well explained with visual diagrams where any single area let's say AWS databases is covered at a high level in one single image. This aids in recalling the concepts and applying them to scenario specific questions in the exam correctly.

Week 3:-

Go through a cloud Guru Videos,  FAQs  for all major AWS services in AWS.
Review the AWS Whitepapers

AWS Well-Architected Framework Whitepaper
AWS_Risk_and_Compliance_Whitepaper
AWS_Security_Whitepaper
AWS_Cloud_Best_Practices
AWS_Overview
AWS_Storage-Options


Week 4:-

Take Practice Tests

Braincert AWS Solutions Architect – Associate SAA-C01 Practice Exams, which provide extensive scenario based questions
Udemy AWS Solutions Architect – Associate SAA-C01 Practice Exams


Also Refer to CheatSheet before exam day here




Troubleshooting EC2 instances 


References :-

https://www.udemy.com/aws-architect/learn/
https://www.udemy.com/linux-academy-aws-certified-solutions-architect-associate/learn/
https://www.udemy.com/aws-certified-associate-architect-developer-sysops-admin/learn/
https://www.udemy.com/aws-certified-solutions-architect-associate/learn/