Linux as the Backbone of Kubernetes and Hadoop Ecosystems

The directory /nfs   should be created in your node/server. The nfs mount can be mount as a “soft mount” or as a “hard mount” these mount option define the how the nfs client should be handle nfs crash/failure . We will see the difference between hard mount and soft mount. Soft mount :- suppose you have mount the nfs by using “ soft mount’ when a program request a file from nfs server. Nfs demon will try to retrieve the data from the nfs server. If doesn’t get any response from nfs server due to some failure or crash on nfs server. Then nfs client report an error to the process on the client machine requesting the file access the Advantage “fast responsiveness”   it doesn’t wait to the nfs server to respond. The Main Disadvantage of this method is data corruption or loss of data so this is not the recommended option to use.  [root@sadeek ~]# showmount -e 172.28.50.109 Export list for 192.168.0.105: /nfs * Soft mounting (Temporary Mounting)...

For nagios configuration you can  click here

for this you can    click here  

Need to monitor Linux server performance? Try these built-in command and a few add-on tools. Most Linux distributions are equipped with tons of monitoring. These tools provide metrics which can be used to get information about system activities. You can use these tools to find the possible causes of a performance problem. The commands discussed below are some of the most basic commands when it comes to system analysis and debugging server issues such as: Finding out bottlenecks. Disk (storage) bottlenecks. CPU and memory bottlenecks. Network bottlenecks 1: top - Process Activity Command The top program provides a dynamic real-time view of a running system i.e. actual process activity. By default, it displays the most CPU-intensive tasks running on the server and updates the list every five seconds . Commonly Used Hot Keys The top command provides several useful hot keys: Hot Key Usage t Displays summary information off and on. m Displays memory information off...

Extended n file system ext2 : - Introduced with kernel 1.0 in 1993 - Flexible can handle upto 4TB - super block feature increase file system performance - ext2 reserve 5% of disk space for root - ext2 is popular on USB and other solid-state devices.   This is because it does not have a journaling function.   so it generally makes fewer reads and writes to the drive,   effectively extending the life of the device . -  NO journalalizm ext3 : - Provide all the feature of ext 2 + journaling and backward compatibility . - can upgrade ext2 to ext3 without loss of data. - journaling feature speed up the system to recover the state after power-failure   or improper mount unmount etc. - Example: In ext2 in an improper unmount or in-between power-off etc.. so in time   of receiver it checks whole file system .   But in ext3 it keeps record of uncommitted file transactions and checks applied   on on them so system will come back up in fa...

I know for a beginner how tough to find which types of question an interviewer will ask to ?? ...   These are the some Question for Reference...    1.      Diff between RHEL 4 & 5 & 6 2.      About boot proces 3.      Types of DNS? 4.      how dns works? 5.      what is squid? 6.      port number of data ftp, ftp, telnet, smtp, sql 7.      what is sendmail hows it's works 8.      How to block downloading in squid 9.      How you handle Load on server? 10. Fields in crontab? 11. Any backup tools you know? 12. How to update your server? 13. rpm commands to update, erase, install etc... 14. Use squid to do authentication of users on browser? 15. Use of NFS and samba? 16. Diff NfS & Samba? 17. What is SeLinux? 18. Default cache size in Squid? 19. I want to assign NISdomainnam...

Linux Cron utility is an effective way to schedule a routine background job at a specific time and/or day on an on-going basis.   Linux Crontab Format MIN HOUR DOM MON DOW CMD Table: Crontab Fields and Allowed Ranges (Linux Crontab Syntax) Field Description Allowed Value MIN Minute field 0 to 59 HOUR Hour field 0 to 23 DOM Day of Month 1-31 MON Month field 1-12 DOW Day Of Week 0-6 CMD Command Any command to be executed. Scheduling a Job For a Specific Time Every Day The basic usage of cron is to execute a job in a specific time as shown below. This will execute the Full backup shell script (full-backup) on 10th June 08:30 AM . Please note that the time field uses 24 hours format. So, for 8 AM use 8, and for 8 PM use 20. 30 08 10 06 * /home/Sadeek/full-backup 30 – 30th Minute 08 – 08 AM 10 – 10th Day 06 – 6th Month (June) * – Every day of the week Schedule a Job For More Than One Instance (Twice a Day) The following script take a incremental b...

You can click below on some Basic Commands    :   Basic Commands    &  Basic Commands 2

1. ext4 file system is introduced. 2. xen is removed and kernel virtualization machine (KVM) is introduced. 3. neat command is removed. 4. portmap service is removed. 5. iscsi is introduced, which supports for SAN. 6. rpmbuild is available, which is used to create our own rpms. 7. File encyption is added. 8. palimpsest is available for disk management. 9. Virtual machine will run only on 64bit processors. 10. postfix service is recommended instead of sendmail service

Linux User Disk Quota Implementation What is disk quota? Ans :  Disk quota is  restricting the  disk-space   usage to the users . We have to remember one  thing when we are dealing with disk quota i.e. Disk Quota can be applied only on  disks/partitions  not on  files and folders . how we can implement disk quota? Disk quota can be implemented in   two   ways a.   On   INODE b.   On   BLOCK What is an INODE? Ans :   In Linux every object is consider as   file , every file will be having an   inode number   associated and this is very much easy for computer to recognize where the file is located. Inode   stands for   Index Node , and is the focus of all file activities in the UNIX file-system. Each file has one inode that defines the file’s type (regular, directory, device etc), the location on disk, The size of the file, Access permissions, Access times. Note ...