diff --git a/README.md b/README.md
index 82d6e09..3d3eac6 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,7 @@
:information_source: This repo contains questions and exercises on various technical topics, sometimes related to DevOps and SRE :)
-:bar_chart: There are currently **1537** questions
+:bar_chart: There are currently **1540** questions
:books: To learn more about DevOps and SRE, check the resources in [devops-resources](https://github.com/bregman-arie/devops-resources) repository
@@ -79,6 +79,12 @@
+## Linux Master Application
+
+A completely free application for testing your knowledge on Linux
+
+
+
## DevOps
@@ -363,22 +369,11 @@ There are multiple ways to answer this question (there is no right and wrong her
What is Chaos Engineering?
+Wikipedia: "Chaos engineering is the discipline of experimenting on a software system in production in order to build confidence in the system's capability to withstand turbulent and unexpected conditions"
+
Read about Chaos Engineering [here](https://en.wikipedia.org/wiki/Chaos_engineering)
-
-What is an error budget?
-
-
-
-What are MTTF (mean time to failure) and MTTR (mean time to repair)? What these metrics help us to evaluate?
-
- * MTTF (mean time to failure) other known as uptime, can be defined as how long the system run before if fails.
- * MTTR (mean time to recover) on the other hand, is the amount of time it takes to repair a system.
- * MTBF (mean time between failues) is the amount of time between failures of the system. These errors can be intermittent or fatal.
-
-
-
What is "infrastructure as code"? What implementation of IAC are you familiar with?
IAC (infrastructure as code) is a declerative approach of defining infrastructure or architecture of a system. Some implementations are ARM templates for Azure and Terraform that can work across multiple cloud providers.
@@ -475,16 +470,57 @@ Note: cross-dependency is when you have two or more changes to separate projects
Have you contributed to an open source project? Tell me about this experience
+
+What is Distributed Tracing?
+
+
#### SRE
What are the differences between SRE and DevOps?
+
+Google: "One could view DevOps as a generalization of several core SRE principles to a wider range of organizations, management structures, and personnel."
+
+Read more about it [here](https://sre.google/sre-book/introduction)
What SRE team is responsible for?
Google: "the SRE team is responsible for availability, latency, performance, efficiency, change management, monitoring, emergency response, and capacity planning of their services"
+
+Read more about it [here](https://sre.google/sre-book/introduction)
+
+
+
+What is an error budget?
+
+Atlassian: "An error budget is the maximum amount of time that a technical system can fail without contractual consequences."
+
+Read more about it [here](https://www.atlassian.com/incident-management/kpis/error-budget)
+
+
+
+What do you think about the following statement: "100% is the only right availability target for a system"
+
+Wrong. No system can guarantee 100% availability as no system is safe from experiencing zero downtime.
+Many systems and services will fall somewhere between 99% and 100% uptime (or at least this is how most systems and services should be).
+
+
+
+What are MTTF (mean time to failure) and MTTR (mean time to repair)? What these metrics help us to evaluate?
+
+ * MTTF (mean time to failure) other known as uptime, can be defined as how long the system runs before if fails.
+ * MTTR (mean time to recover) on the other hand, is the amount of time it takes to repair a broken system.
+ * MTBF (mean time between failures) is the amount of time between failures of the system.
+
+
+
+What is the role of monitoring in SRE?
+
+Google: "Monitoring is one of the primary means by which service owners keep track of a system’s health and availability"
+
+Read more about it [here](https://sre.google/sre-book/introduction)
## Jenkins
@@ -2468,7 +2504,19 @@ Using the `mv` command.
Using a pipe in Linux, allows you to send the output of one to another (also called redirection). For example: `cat /etc/services | wc -l`
-### Linux FHS
+
+Fix the following commands:
+
+ * sed "s/1/2/g' /tmp/myFile
+ * find . -iname \*.yaml -exec sed -i "s/1/2/g" {} ;
+
+
+
+sed 's/1/2/g' /tmp/myFile
+ find . -iname "*.yaml" -exec sed -i "s/1/2/g" {} \;
+
+
+#### Linux FHS
In Linux FHS (Filesystem Hierarchy Standard) what is the /?
@@ -2911,14 +2959,20 @@ related to the file like its size, owner, permissions, etc.
* File size
* File name
* File timestamp
+
+File name (it's part of the directory file)
How to check which disks are currently mounted?
+
+Run `mount`
-You run mount command but you get no output. How would you check what mounts you have on your system?
+You run the mount command but you get no output. How would you check what mounts you have on your system?
+
+`cat /proc/mounts`
@@ -2973,7 +3027,7 @@ There are many answers for this question. One way is running `df -T`
-What do you know about LVM?
+What is LVM?
@@ -2982,6 +3036,8 @@ There are many answers for this question. One way is running `df -T`
* PV
* VG
* LV
+
+
@@ -3005,22 +3061,10 @@ There are many answers for this question. One way is running `df -T`
-Fix the following commands:
-
- * sed "s/1/2/g' /tmp/myFile
- * find . -iname \*.yaml -exec sed -i "s/1/2/g" {} ;
-
-
-
-sed 's/1/2/g' /tmp/myFile
- find . -iname "*.yaml" -exec sed -i "s/1/2/g" {} \;
-
-
-
-What is stored in each of the following logs?
+What is stored in each of the following logs?
* /var/log/messages
- * /var/log/boot.log
+ * /var/log/boot.log
@@ -7880,6 +7924,8 @@ a = f()
Explain monitoring. What is it? What its goal?
+
+Google: "Monitoring is one of the primary means by which service owners keep track of a system’s health and availability".
diff --git a/images/linux_master.jpeg b/images/linux_master.jpeg
new file mode 100644
index 0000000..44a1a83
Binary files /dev/null and b/images/linux_master.jpeg differ