Month: June 2009

Linux User info gathering commands

MONITORING USERS User-management is always one of the basic tasks for Linux administrators, here we are going to see some basics user related “Monitoring Commands”. 1) “finger” is a command which will give full details about user properties such as name, login, shell what he is using etc. Syntax: #finger username Example: [root@localhost ~]# finger root Login: root Name: root Directory: /root Shell: /bin/bash On since Sat Jun 6 19:20 (EDT) on tty1 4 hours 12 minutes idle On since Sun Jun 7 02:18 (EDT) on pts/0 from :0.0 On since Sun Jun 7 03:48 (EDT) on pts/1 from :0.0 16 minutes 9 seconds idle New mail received Sun Jun 7 04:02 2009 (EDT) Unread since Sat Jun 6 22:17 2009 (EDT) No Plan. Here you can see so many user related information one security information you can see is when he loged in last time and from where he loged in etc. 2)“id” is one more command which will show the user details such as his primary group and his secondary group. Syntax: #id username Example: [root@localhost ~]# id root uid=0(root) gid=0(root) groups=0(root),1(bin),2(daemon),3(sys),4(adm),6(disk),10(wheel) context=root:system_r:unconfined_t:SystemLow–SystemHigh [root@localhost ~]# 3)“chage“ is one more command which is used to see user related “threshold details” such as user disable time etc. Syntax: #chage -l username Example: [root@localhost ~]# chage -l root Last password change : Jun 06, 2009 Password expires : never Password...

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RAID01 Vs RAID10

So what is the difference between RAID01 and RAID10? This is bit tricky question, Recently I came to know about this one in an interview. so do both are same? No both are not same. When we are dealing with RAID01 we are actually implementing RAID0 first then RAID1 on it. Ok little bit confused? Let me put it in this way RAID0 is nothing but stripeset writing of data and RAID1 is Mirring of data on to disks.For example let us take 8 disks, so first we are writing whole data on 4 disks then we are mirring it on to remaining disks. Where as in RAID10 we are first mirring disk and then striping data on mirrered disks In general RAID01 is “a mirrior of 2 strips” and RIAD10 is “a single strip on mirrered disks” So here one more question arises… which one is good? RAID10 is good, the difference is that the chance of system failure with two drive failures in a RAID 0+1 system with two sets of drives is (n/2)/(n – 1) where “n” is the total number of drives in the system. The chance of system failure in a RAID 1+0 system with two drives per mirror is 1/(n – 1). So, using the 8 drive systems shown in the diagrams, the chance that loosing a second drive would bring down the...

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Linux interview questions :FTP

LINUX INTERVIEW QUESTIONS : FTP One of my friend asked me why there is no answers for So many interview questions, basically most of the interview questions which are on this site are the interviews which happened to me so. At that time I am not able to Answer some of the questions, so from today on words I will try to post all the interview questions with answers, If you feel these answers are wrong you can feel free to comment with proof so that i can modify my posts. 1)  What is the difference between TFTP and...

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ABOUT ME..!

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My name is Surendra Kumar Anne. I hail from Vijayawada which is cultural capital of south Indian state of Andhra Pradesh. I am a Linux evangelist who believes in Hard work, A down to earth person, Likes to share knowledge with others, Loves dogs, Likes photography. At present I work at Bank of America as Sr. Analyst Systems and Administration. You can contact me at surendra (@) linuxnix dot com.