Questions specifically about Linux, as opposed to Unix-like systems in general, or to questions about a specific distribution or program.

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15
votes
4answers
628 views

What is new in Kernel 3.0?

I understand this is somewhat less Ubuntu related, but it affects it. So,what is so new about it that Linus decided to name it 3.0? I'm not trying to get information about the drivers that got into ...
15
votes
3answers
733 views

How much does the Linux kernel change in one year?

How can I get statistics about how much (in percents) the Linux kernel source code changes in one year?
15
votes
4answers
8k views

Resume transfer of a single file by rsync

In Ubuntu, I want to copy a big file from my hard drive to a removable drive by rsync. For some other reason, the operation cannot complete in a single run. So I am trying to figure out how to use ...
15
votes
1answer
506 views

How is new hardware support added to the linux kernel?

Imagine there's a company A that releases a new graphics adapter. Who manages the process that results in this new graphics adapter being supported by the Linux kernel in the future? How does that ...
15
votes
2answers
2k views

When was a process started

To know when was a process started, my first guess was to check the time when /proc/<pid>/cmdline was written/modified the last time. ps also shows a START field. I thought both of these ...
15
votes
1answer
6k views

What is difference between User space and Kernel space?

Is Kernel space used when Kernel is executing on the behalf of the user program i.e. System Call? Or is it the address space for all the Kernel threads (for example scheduler)? If it is the first ...
15
votes
3answers
4k views

How to fix Ctrl + arrows in Vim?

I am using Putty -> Suse box -> vim 7.2 combo for editing and want to remap Ctrl + arrows combo to a particular task. But for some reason, Vim ignores the shortcut and goes into insert mode and ...
15
votes
2answers
3k views

How does one change the delay that occurs after entering an incorrect password?

After entering an incorrect password at a login prompt, there s an approximately 3-second delay. How can I change that on a Linux system with PAM?
15
votes
2answers
272 views

Open man page and search for string in a single command

Instead of doing man chmod and then /a+x to jump to the first section in the chmod man page that mentions a+x, I would like to know if there is a way to open the man page to a specific search string, ...
15
votes
2answers
8k views

Why is swappiness set to 60 by default?

I just read some stuff about swappiness on Linux. I don't understand why the default is set to 60. According to me this parameter should be set to 10 in order to reduce swap. Swap is on my hard ...
15
votes
5answers
3k views

Can ps display only non kernel processes on Linux?

How can I ask ps to display only user processes and not kernel threads? See this question to see what I mean...
15
votes
6answers
294 views

What do I need to be aware of if I want to write an application that will run on any Linux distro?

I'm planning on writing an app that I would like to be able to run on any Linux installation without having to rewrite any of the code in doing so (except maybe the interface, GNOME vs KDE, etc). I'm ...
15
votes
7answers
10k views

Linux boot loaders supporting full disk encryption?

Are there any Linux boot loaders supporting full disk encryption (a la TrueCrypt). I know there was work towards adding encryption support to GRUB2, but this does not seem to be ready yet. Any other ...
15
votes
5answers
3k views

How to start a new Linux distro?

Some of my friends and I are interested in starting a new Linux distro. How do we do that? What do we need to plan? Backstory I represent a community of Linux sysadmins/implementors whose special ...
15
votes
2answers
424 views

Can I list the filesystems a running kernel can support?

I'm trying to detect what filesystems a kernel can support. Ideally in a little list of their names but I'll take anything you've got. Note that I don't mean the current filesystems in use, just ones ...
15
votes
2answers
35k 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 ...
15
votes
2answers
910 views

Linux: Total swap used = swap used by processes +?

So, I'm trying to do some investigation on where does swap use come from in a system with high swap usage: # free total used free shared buffers cached Mem: ...
15
votes
2answers
9k views

Booting native Arch Linux on an Android device

I have a Galaxy Note 10.1 (n8010) and I want to make it boot Arch Linux natively. I mean boot Arch Linux instead of android. All that I need is to alter the initramfs, which I can't find anywhere in ...
14
votes
3answers
961 views

Why do Linux people always say to read the manual? [closed]

Why do Linux people always say to read the manual when it would be so much easier to just give you an answer? There's no manual! It didn't come with one.
14
votes
2answers
1k views

Accidently created a file called -X, how can I delete it? [duplicate]

Possible Duplicate: How do I delete a file whose name begins with “-” (hyphen a.k.a. dash or minus)? Like an idiot, I ran this command: tar -cf -X awstats-icon icon ...
14
votes
5answers
6k views

What is the difference between ls and l?

I accidentally typed l instead of ls today and found that the command still printed a list of the files in my current directory. Trying l --help brings up the help file for ls suggesting that l is ...
14
votes
4answers
954 views

Why not always use rsync?

I wanted to ask is there any reason not to use rsync for everything and abandon cp? I wasn't aware of rsync and now I don't know why cp is ever needed.
14
votes
5answers
3k views

Why do most linux distros default gnome?

Why the default desktop environment of most popular linux distros is gnome? KDE seems to me an equally good desktop environment. Is it for licence reason? historic? or else?
14
votes
3answers
593 views

Move files and change ownership at the sametime

On Linux (Debian, Ubuntu Mint...), Is there any option command or something that I can use to transfer files to another user without having to do : sudo mv /home/poney/folderfulloffiles ...
14
votes
8answers
7k views

How to determine which sd* is usb? [duplicate]

Possible Duplicate: How to know if /dev/sdX is a connected USB or HDD? The output of ls /dev/sd* on my system is - sda sda1 sda2 sda3 sda4 sda5 sda6 sda7 sdb sdc sdc1 sdc2 ...
14
votes
6answers
9k views

Execute a specific command in a given directory without cd'ing to it?

Is there a way to execute a command in a different directory without having to cd to it? I know that I could simply cd in and cd out, but I'm just interested in the possibilities of forgoing the extra ...
14
votes
1answer
18k views

recursive mkdir

Is there a linux command that I'm overlooking that makes it possible to do something along the lines of: (pseudo) $ mkdir -R foo/bar/zoo/andsoforth Or is there no alternative but to make the ...
14
votes
4answers
2k views

How is the linux graphics stack organised?

Can anybody explain(hopefully with a picture), how is the linux graphics stack organised? I hear all the time about X/GTK/GNOME/KDE etc., but I really don't have any idea what they actually do and how ...
14
votes
3answers
7k views

How can I reserve a block of memory from the Linux kernel?

I have a device that needs a block of memory that is reserved solely for it, without the OS intervening. Is there any way to tell BIOS or the OS that a block of memory is reserved, and it must not ...
14
votes
2answers
1k views

Why writing to /dev/random does not make parallel reading from /dev/random faster?

Typically reading from /dev/random produces 100-500 bytes and blocks, waiting for an entropy to be collected. Why doesn't writing information to /dev/random by other processes speed up reading? ...
14
votes
5answers
7k views

Using different versions of Python

Background: Since I develop python programs that must run on different python versions, I have installed different versions of python on my computer. I am using FC 13 so it came with python 2.6 ...
14
votes
9answers
49k views

Cannot enable network after CentOS 6.3 fresh install

I am trying to perform a fresh CentOS 6.3 installation then run various yum commands such as yum install httpd. The installation runs fine, however I cannot run any network based commands like yum I ...
14
votes
3answers
13k views

How can I tell what version of linux I'm using?

Often times I will ssh into a new client's box to make changes to their website configuration without knowing much about the server configuration. I have seen a few ways to get information about the ...
14
votes
6answers
5k views

How does Linux kernel compare to microkernel architectures?

I read once that one advantage of a microkernel architecture is that you can stop/start essential services like networking and filesystems, without needing to restart the whole system. But considering ...
14
votes
5answers
16k views

How to list all files in the size order

I would like to list all files in the order of big to small in size and the files could be present anywhere in a certain folder.
14
votes
2answers
8k views

Get the chmod numerical value for a file

In FreeBSD and also in Linux, how can I get the numerical chmod value of a file? For example, 644 instead of -rw-r--r--? I need an automatic way for a Bash script.
14
votes
2answers
2k views

Can the same ext4 disk be mounted from two hosts, one readonly?

I know that mounting the same disk with an ext4 filesystem from two different servers (it's an iSCSI vloume) will likely corrupt data on the disk. My question is will it make any difference if one of ...
14
votes
5answers
16k views

How to see disk details like manufacturer in Linux

With sfdisk -s I can see the disk capacity as follows: $ sfdisk -s /dev/cciss/c0d0: 143338560 total: 143338560 blocks How do I see disk details like disk manufacturer? I tried hdparm, but got an ...
14
votes
1answer
1k views

What is Linux doing differently that allows me to remove/replace files where Windows would complain the file is currently in use?

The example I have is Minecraft. When running Bukkit on Linux I can remove or update the .jar files in the /plugins folder and simply run the 'reload' command. In Windows, I have to take the whole ...
14
votes
3answers
4k views

Why does the 'bin' user need a login shell?

During an audit of /var/log/auth.log on one of my public webservers, I found this: Jan 10 03:38:11 Bucksnort sshd[3571]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 ...
14
votes
3answers
2k views

How to use three monitors on a laptop?

I have a laptop running Ubuntu 9.04 with a dual-head setup: laptop panel + external monitor. I'd like to add another monitor but the laptop has a single VGA port, so my question is: what are my ...
14
votes
3answers
2k views

Determining Specific File Responsible for High I/O

This is a simple problem but the first time I've ever had to actually fix it: finding which specific files/inodes are the targets of the most I/O. I'd like to be able to get a general system overview, ...
14
votes
1answer
2k views

per process swapiness for linux

/proc/sys/vm/swappiness is nice but i want a knob that's per process like /proc/$PID/oom_adj so that i can make certain processes less likely than others to have any of their pages swapped out unlike ...
14
votes
3answers
4k views

Are multiple @daily crontab entries processed in order, serially?

I want two jobs to run sometime every day, serially, in exactly the order I specify. Will this crontab reliably do what I want? @daily job1 @daily job2 I'm assuming they run one after the other, ...
13
votes
10answers
2k views

What linux is best suited for people new to computers?

What would be the easiest linux for people who are new to computers? The computers here have 256Mb RAM with 40GB hard-disks. UPDATE: Most of them apparently have more than 265MB of RAM with some ...
13
votes
10answers
23k views

List partition labels from the command line

Is there a command that will list all partitions along with their labels? sudo fdisk -l and sudo parted -l don't show labels by default. EDIT: (as per comment below) I'm talking about ext2 labels - ...
13
votes
4answers
7k views

What is the meaning of $? in a shell script?

When going through one shell script, I saw the term "$?". What is the significance of this term?
13
votes
7answers
13k views

Disable screen blanking on text console

I'm running linux clusters, mostly on SLES10. The servers are mostly blades, accessed via remote console. There is a real console in the server room, but switched off. I would like to disable the ...
13
votes
6answers
1k views

Can a Linux command have capital letter(s)?

Can a Linux command have capital letter(s)? I know it's supported but i want to be sure if it's a "problem" or considered "not a good thing"?
13
votes
5answers
11k views

How can I limit the bandwidth used by a process?

I have a CentOS 5.7 server that will be backing up its files nightly. I am concerned that visitors to the various sites that the server hosts will experience degraded performance while the backup is ...