1
vote
3answers
26 views

Linux SW RAID and physical volumes

In each guide about software RAID in Linux, I could find online I see that people usually create/assemble RAID devices using partitions, like: mdadm --create --verbose /dev/md0 --level=5 ...
5
votes
3answers
1k views

Why is the 'sudo' password different than the 'su root' password

On my personal machine, I often type sudo in front of certain commands in order to accomplish administrative tasks. I had hoped to avoid doing this throughout the day, by typing su root and providing ...
5
votes
0answers
96 views

Logging violations of rules in limits.conf [duplicate]

I'm trying to log the details of the programs that where failed due to the limit cap defined in the limits.conf. My initial plan was to do it using the audit system. The idea was to track the system ...
1
vote
1answer
408 views

How to prevent users from renaming files while providing write permissions on Linux [closed]

For some special purpose, I want to prevent non-root users of the Linux Server from changing or renaming the filenames. However, they can modify and write to the contents of the file. How to do this ...
0
votes
5answers
151 views

change of Unix default directory structure [closed]

Is it possible to change the default Unix/Linux directory structure? I mean by configuration and without need to change the kernel. Or if the kernel has to be edited, how hard is such task? Is the ...
7
votes
3answers
208 views

Linux/Unix variant for training system administrators

Is there a Linux/Unix based operating system used for training sysadmins? Some bugs would be deliberately included in the system and the training candidate is supposed to solve all of them. It should ...
4
votes
1answer
2k views

How to get Oracle java 7 to work with setcap cap_net_bind_service+ep

I am trying to grant the java executable the right to open ports below 1024 on Linux. Here is the setup /home/test/java contains the Oracle Server JRE 7.0.25 CentOS 6.4 Here is what getcap ...
0
votes
1answer
216 views

Which book of those two should i read to study networking for Unix/Linux administrator? [closed]

I'm quite a beginner to networking, I want to get the information that i need as a Linux/Unix admin. I have two books in hand right now: TCP/IP Illustrated, Volume 1: The Protocols UNIX and ...
0
votes
1answer
155 views

LPIC-1 for non-professional experienced user

I am interested in trying out the LPIC-1 certification however I am slightly worried that I may not have the needed professional experience to pass. I am still studying hard and running a lab with a ...
5
votes
4answers
4k views

How can I assign an initial/default password to a user in Linux?

I found a guide that explains how to set a user's password. I'm trying to automate it and send an e-mail to the user like: userid created with password XYZ. request to change the initial password. ...
2
votes
2answers
383 views

How do I check active crons?

I'm trying to hunt down a cron job (or the equivalent) which I know is running, but I can't find it in the default cron files for my system (FreeBSD / Linux / BSD). How can I tell which ones are ...
5
votes
5answers
419 views

Which tasks to learn and which books to read to become more skilled at Unix/Linux internals? [closed]

I recently interviewed at a major company and did well on programming questions such as: "What is the time complexity of quicksort? What is the opposite in C of malloc? What is the opposite in ...
6
votes
5answers
462 views

What are the recommended ways of defending a remote *nix install from a hamfisted admin?

Once in a while (often a long while), I have a difficulty where I execute a command that completely screws up a Linux machine. Most recently, I accidentally mounted-again the root partition (thinking ...
7
votes
3answers
642 views

Linux Bulk/Remote Administration

Beside our internal IT infrastructure, we've got around 500 Linux machines hosting our services for the on-line world. They are grouped in a bunch of clusters like Database A-n, Product A-n, NFS, ...
0
votes
1answer
1k views

The TIME field in ps -ef

When I do ps -ef, I see "TIME" field. What does this field mean? From what I understand, this tells the actual CPU time, that the process got (amidst all the context switching). Does the TIME field ...
5
votes
2answers
5k views

How to see complete list of processes in top

When I do 'top', I learn that there are many processes running out of which many are in sleep state. I need to see complete snapshot of all processes at that point. the 'top' is able to show listing ...
9
votes
2answers
5k views

How to know reason of a process going to sleep state and wake it up?

When I do 'top' , I see my perl script process in 'S' state. Is there a way to know, what is making this perl process go in sleep state and ways to wake it up? Any way to debug to give more insights ...
0
votes
1answer
697 views

Need help with understanding output of ps -ef on linux

When I do ps -ef on my Linux box, I get: UID PID PPID C STIME TTY TIME CMD Please help me with meaning of C,TIME. is the TIME , the actual cpu time allocated to the process?
17
votes
2answers
38k views

How can I change a user's default group in Linux?

Being new to Linux administration, I'm a little confused about the following commands: useradd usermod groupadd groupmod I've just finished reading the user administration book in the Linux/Unix ...
1
vote
1answer
449 views

How can I learn some advanced logrotate techniques?

The logrotate section in the Linux administrator's handbook is very brief. The man page is ok but lacks examples. Where can I find some more comprehensive information, examples, and best-practice ...
1
vote
3answers
155 views

How to clean up my desktop?

Now, I see that my desktop running rhel 5.6 has run out of space. Now I need to clean it up. There must be some unintentional files adding up. What I would like to be able to do is list the files in ...
5
votes
1answer
748 views

What is the routing behaviour when two or more default routes?

I have two ISP at the time, connected to the same machine. I added both of them in the routing table as default. However, only one connection is used. $ route Kernel IP routing table Destination ...
0
votes
1answer
442 views

What unix certifications are available? Are there any self-taught?

I have a friend who is a Red Hat Certified Engineer. I also know there is the Linux Professionals Institute LPIC-1, 2, & 3. Are there other popular ones? How do I pick one to start with?
0
votes
1answer
950 views

Fun, tricky and hard questions for Unix/Linux Admin interview [closed]

I am now preparing process of recrutation for group of Unix/Linux Administrators and I was wondering if maybe you have idea for fun or tricky or hard questions to ask the candidates in order to test ...
0
votes
1answer
342 views

Smitty like solution under Linux or BSD?

Are there any solutions similar to AIX smit for Linux based OSes? Basically this would be some kind of 'terminal menu-driver' script collection perhaps using ncurses for doing things that system ...
1
vote
1answer
188 views

Mass update of /etc/ldap.secret

I have a group of servers authenticating against an LDAP server. I would like to be able to periodically update the /etc/ldap.secret file with an updated secret. I've written a small script that reads ...
10
votes
1answer
5k views

How can I configure cgroups to fairly share resources between users?

There used to be a kernel config option called sched_user or similar under cgroups. This allowed (to my knowledge) all users to fairly share system resources. In 2.6.35 it is not available. Is there a ...
3
votes
4answers
230 views

How do you work with old servers?

I've recently fallen into doing more work on LAMP servers, which is pretty new to me. At first it wasn't a problem migrating my preference files, but as I've grown and learned more, my preferences ...