#System-Administration

മരണം അനിവാര്യമായ ഒന്നാണ്, ഒരാൾ തന്റെ രാജ്യത്തോടും ജനങ്ങളോടുമുള്ള കടമ നിർവഹിച്ചു കഴിഞ്ഞാൽ അയാൾക്ക് സമാധാനത്തോടെ വിശ്രമിക്കാം. 2004 ലെ ഒരു പുലർകാലം, ഞാനും സബീഷും തിരുവനന്തപുരത്തേക്കുള്ള ഇന്റർസിറ്റിയിൽ യാത്ര ചെയ്യുകയാണ്. തിരുവനന്തപുരത്ത് ചെന്ന് പ്രതിപക്ഷ നേതാവ് സഖാവ്.വി.എസ്.അച്യുതാനന്ദനെ കാണണം. ഉദ്ദേശം, പുതിയതായി നിർമ്മിച്ച സോഫ്ട്വെയർ അതിന്റെ സാധ്യതകൾ, അതെങ്ങിനെ കേരളത്തിലെ വിദ്യാഭ്യാസ മേഖലക്കു ഗുണകരമാകും എന്ന കാര്യങ്ങൾ അദ്ദേഹത്തെ ധരിപ്പിക്കണം. ലക്ഷ്യം ഇതാണെങ്കിലും ഇതെങ്ങനെ നടപ്പിലാക്കും എന്നു അറിയില്ലായിരുന്നു. വി.എസ്സ് അന്ന് പൊതു ഇടങ്ങളിലെല്ലാം സ്വതന്ത്ര സോഫ്ട്വെയറുകൾ പ്രചരിപ്പിക്കുന്നതിനെ പറ്റി ഒക്കെ ഒരുപാട് സംസാരിക്കുമായിരുന്നു. അദ്ദേഹത്തെ കാണാൻ നേരത്തേ ഉള്ള അനുമതി ഒന്നുമില്ലായിരുന്നു. ഏതാണ്ട് ആലപ്പുഴ എത്തിയപ്പോഴാണു, സുകുമാരൻ വൈദ്യർ എന്നൊരാളെ ട്രെയിനിൽ വച്ചു പരിചയപ്പെടുന്നത്. [Read More]

Understanding the Difference Between SFTP and FTPS SFTP: SSH File Transfer Protocol FTPS: File Transfer Protocol over SSL Understanding the Difference Between SFTP and FTPS When it comes to secure file transfer protocols, two popular options are SFTP (SSH File Transfer Protocol) and FTPS (File Transfer Protocol over SSL). While both protocols serve the same purpose of secure file transfer, they differ in various aspects. In this blog post, we will delve into the key differences between SFTP and FTPS, along with a few use cases for each. [Read More]

Your Linux box is slow and you are running top command. Well, you are seeing a lot of metrics, what does these values means. Major CPU Status Idle, the percentage of idle CPU Running a user space program, a User application running. It could be a compiler, Email client Running the kernel, Handling an interrupts, managing resources The above said meta states can be divided. User space programs can be categorized as those running under their initial priority level or those running with a nice priority. [Read More]

It happend, What now ? Get into battlefield Monitoring Cell Engineering Cell Customer success Cell Administrative Cell You brought it back Post incident measures It happend, What now ? Its a nightmare for a every cloud provider. Even you take all the measures to prevent, it could be happen. Its called Disaster. You are serving a lot of customers, you have to protect their interests. Because they are also a service provider to their customers. [Read More]

Preface Core services may not running Two different host types No Shared volume No enough Quota Apparmor in place The source compute host swapped No valid host found Further reading Preface Recently I had faced an interesting question during an Interview. Question was, One of the virtual machine is in error state, how will you troubleshoot?. Well, thats a general question and all of them went through it atleast once? [Read More]

What is an Overcommit in cloud ? Overcommitting Memory Overcommitting CPU Why its important in a Public Cloud Where are the Overcommit values in Openstack Well, I have a very special requirement Solution Create the aggregate Add your computes to this Aggregate Setting up Overcommit values to this particular Aggregate How the Guest VM know, i should go to this Aggregate Inject Flavor metadata Check the flavor now Add few filters in nova Disable the current allocation from nova Restart nova Workflow Further Reading What is an Overcommit in cloud ? [Read More]

Courtesy Preface Assumptions Solution Import Route Target Security Group Futher Reading Courtesy Bytes around me :-) Preface Sharing Private network is a common use case in Cloud Environment. Normally RBAC will help you to achieve. Since Newton release, this feature is Available. But the question is which SDN you are using in your Environment. If you are using Opencontrail 3.2 as SDN, you cannot go with RBAC. Assumptions Openstack Release Ocata Opencontrail 3. [Read More]

Courtesy Preface Use Case Implementation New Routing Table Add Policy Rules Flush the routing cache Testing Rules Further Reading Courtesy Tutorial credit goes to [Omar Hamad ] (https://www.linkedin.com/in/omermahgoub/) the real Architect I have seen in last few years. Working with him for the past 3 Years, and learned a Lot. We are going to miss u :( Preface When configuring a Linux host with multiple interface, each with its own default gateway, ensuring route symmetric is a bet challenging for any given pair of endpoint. [Read More]

Preface History Using ! Using part of Command Preface One of the fancy feature of Bash is the command history. History will store all the command run by the User, which will be in /home/$USER/.bash_history. This will help the user to edit / reclass previously applied commands. To get a command previous run in command you can use UP arrow or DOWN arrow keys. History 288 cd layouts/ 289 ls 290 cd . [Read More]

Page loading speed is very important now a days. If you are a web administrator, or a server administrator who is particularly responsible for organizing the things together, then you have to make it a point that users don’t get disappointed while accessing your site – so there is really need for speed curl -s -w 'Testing Website Response Time for :%{url_effective}\n\nLookup Time:\t\t%{time_namelookup}\nConnect Time:\t\t%{time_connect}\nPre-transfer Time:\t%{time_pretransfer}\nStart-transfer Time:\t%{time_starttransfer}\n\nTotal Time:\t\t%{time_total}\n' -o /dev/null http://www.google.com Output for Google. [Read More]