Linux System Administrator Interview Questions and Answer with pdf – Part 01

Linux System Administrator Interview Questions and Answer with pdf – Part 01

What command can be used to findout server architechure (x86 or x64) apart from uname?

• arch

How do u findout the users who are NOT logged in for more than 30 days? which file u will check?

• last , lastlog,   /var/log/wtmp

Whats is called 1.5 stage in boot process of linux?

• Which contains extra code to allow cylinders above 1024, or LBA type drives, to be read. The 1.5 boot loader is stored (if needed) in the MBR or the boot partition.The great thing about GRUB is that it includes knowledge of Linux file systems. Instead of using raw sectors on the disk, as LILO does, GRUB can load a Linux kernel from an ext2 or ext3 file system. It does this by making the two-stage boot loader into a three-stage boot loader. Stage 1 (MBR) boots a stage 1.5 boot loader that understands the particular file system containing the Linux kernel image. Examples include reiserfs_stage1_5 (to load from a Reiser journaling file system) or e2fs_stage1_5 (to load from an ext2 or ext3 file system). When the stage 1.5 boot loader is loaded and running, the stage 2 boot loader can be loaded.”

• So basically, Stage 1 Boot loader is MBR
• Stage 2 Boot loader is GRUB
• Stage 1.5 Boot loader is e2fs_stage1_5
• (Basically this module will load the knowledge of Filesystem to Grub to read the kernel)

When u try to create a file, u got a error that “No space available”. But actually space available on volume? How do u resolve this issue?

• Try this df -i   list inode information instead of block usage [Perhaps are you out of inodes on this file system.], To “rectify it”, remove unwanted files or move them somewhere else.]

How do u extend the LV in Linux?

• First check whether is there free space available in the VG where the LV resides.
• # vgdisplay or
• # vgs
• Now, extend the LV using below command: “L” option to specify the size to be increased.
• # lvextend -L +5G /dev/vg00/lv01
• Finally, extend the File system space: # resize2fs /dev/vg00/lv01

What are the fields in the /etc/passwd file. Explain them?

• There are 7 fields in /etc/passwd:

• <username:x:UID:GID:comment:home directory:shell>
• Username
• Password
• UID
• Primary group ID  Comment /description Home directory path Shell assigned to the user

What command can you use to review boot messages?

• The dmesg command can be used to display the system messages during boot time.

I had written a set of series of articles on interview questions, click on below links
https://opensourcewin.wordpress.com/common-windows-system-network-administrator-questions-with-answers-2.html
On DNS Server https://opensourcewin.wordpress.com/dns-interview-questions-and-answers.html and DNS Server for Linux https://opensourcewin.wordpress.com/dns-server-interview-questions-and-answer-for-linux-part-01.html
On Windows System Admin
https://opensourcewin.wordpress.com/systadmin-int-quest-part1-html.html
https://opensourcewin.wordpress.com/system-administrator-interview-question-with-answers-part-2.html
https://opensourcewin.wordpress.com/windows-server-2008-system-administrator-interview-question-and-answer-part-3.html
https://opensourcewin.wordpress.com/windows-server-2008-interview-questions-and-answers-part-4.html
On Linux https://opensourcewin.wordpress.com/linux-system-administrator-interview-questions-and-answer-with-pdf-part-01.html
On Windows Exchange Server 2007 https://opensourcewin.wordpress.com/exchange-server-2007-interview-question-and-answer.html

Let me know your feedback and suggestions 🙂  and click here to download in pdf format.