Ar. Karthick

Bad and good about changing the job often

2010-10-05T06:34:00.000-07:00

I tempt to write this blog because i was recently in a situation to think deeply about this.
When i write this i work for a company where i do 24/7, no weekend holidays.

Since i love my analytical skill, i like to do some research about the issue on day to day work. But here i do such type of work only on day time. Here i completed 8 month so i was not thinking about to change the company and also my profile would look bad if i change my company now.

At that moment, one my friend had called me to say about one opening in his team. As i had already in bad mood about my current work, i decided to attend the interview but did not decide to go out. Luckily i got the offer which is very good and far more better than current work. There is no night shift and weekend holidays which is i want to.

So, this topic was raised in mind whether it is good or bad to change the job often. As per opinion you can change the job if you are going to get what you want. There will be a lot of opening always for experienced guys and they just need you. But everything depends upon your mind and you need to just enjoy your work wherever you go and should be worried for changing job often.

Linux Interview Questions

2009-12-24T00:16:00.000-08:00

I had come across different interviews and i would like to add these question for others.

1. How will you modify kernel parameters and what parameters you modified recently?

You can modify the kernel parameter temporarily at /proc/sys/kernel/FILES but it will not be a permanent one. You need to modify at /etc/sysctl.conf and run sysctl -p to update it to currently running kernel.

2. When you have 5x100GB harddrive, how much you can use for data storage when you enable RAID 5?

The formula is (N-1)x'Size of each disk' so, 400GB can be used. Remaining will be used for parity details.

3. When you add new storage devices, how the system will detect it and how you will mount it, if it is not added to the server automatically?

If it is IDE device, you can find the device number in /dev/ directory as 'hd(number)' and /dev/sd if it is scsi device. You can find the device there and mount it.

4. How HighAvailability works in VMware?
You need to just explain what is HA and how it works in VMware environment, that's all.

5. What will you do when you get I/O Error?
Usually, this error occurs when superblock corrupts. You need to do find the alternative superblock in the drive by using dumpe2fs command.

dumpe2fs /dev/sda | grep "super"

You can see alternative superblock there in another datablock. Now you need to do the fsck by using another superblock.

e2fsck -b 3278 /dev/sda1 then mount it
mount bs=3278 /dev/sda1 /
PS: Please make sure that the drive is unmount when you do this in root partition.

6. Whethere DNS is TCP or UDP?
Answer is both. When the DNS handles the query it use UDP and when it do the zone transfer it uses TCP.

--- will add more questions ...

2009-12-17T20:54:00.000-08:00

Linux - atime, mtime, ctime

atime - file accessed lastly ( ex. listing the file (ls -l), cat filename will modify access time)
ctime - when file modified lastly such as changing permission, ownership, etc
mtime - when the contents of the file is actually changed

2009-12-15T00:59:00.000-08:00

Some English Idioms that i learn

"bed of roses" - very easy

Fixing DNS issue is not always a bed of roses.

"once in a blue moon" = very rarely :

I go home once in a blue moon.

"on ice" = do nothing about something until a future time

I thought to buy laptop, but i put it on ice due to the unavailability of offer.

"tighten your belt" = spend less money

I have a plan to buy laptop, but i need to tighten my belt due to recession.

Veritas Netbackup -- Guide

2009-09-11T07:31:00.000-07:00

Master server: Controls bacukp and recovery activities
Media server: Manages the writing and reading of data
SAN media server: Is a media server whose license only allows backup of itself
EMM server Manages and allocates resources required for NetBackup operations
Clients: Are machines that have data to be backed up.

Executables are found in:
/usr/openv/netbackup/bin
• NetBackup commands are found in:
/usr/openv/netbackup/bin/admincmd
• Sample scripts are found in:
/usr/openv/netbackup/bin/goodies
• Media manager commands are found in:
/usr/openv/volmgr/bin
• man pages are found in:
/usr/openv/man

The installation process copies the startup/shutdown script (located in
/usr/openv/netbackup/bin/goodies/netbackup) to the init.d
directory and creates links to it from the appropriate rc directory.

For
UNIX, the Global Attributes properties are stored on that master server in the
/usr/openv/netbackup/db/config directory. The Global Attributes
properties affect all operations for all policies and clients

VMWare ESXi

2009-09-11T06:15:00.000-07:00

VMkernel

VMkernel is a POSIX-like operating system developed by VMware and gives same functionality similar to that found in other operating systems, such as process creation and control, signals, file system, and process threads. It is designed specifically to support running multiple virtual machines and provides such core functionality as:
• Resource scheduling
• I/O stacks
• Device drivers

File System
VMkernel uses a simple in-memory file system to hold the ESXi configuration files, log files, and staged patches
ESXi configuration files are found in /etc/vmware and log files are found in /var/log/vmware. Staged patches are uploaded to /tmp.

This file system is independent of the VMware VMFS file system used to store virtual machines

What is VMware Convector:

It is used to convert the physical server into a VM machine and convert the format of VMs between VMWare plateforms. Also, it helps to convert the third party image to VM.

Let me try some story

2009-07-30T15:37:00.000-07:00

Which is perfect !!

This is about the child of studying 5th standard. His name is ravana. He is very punctual for school and he is committed to do his best on everyday. He studies daily whatever the teacher has taught him on everyday. He is also the class leader since he posses good leadership.

Let me continue...

2007-08-17T06:13:00.000-07:00

cool :)