LinuxQuestions.org
Latest LQ Deal: Linux Power User Bundle
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Newbie
User Name
Password
Linux - Newbie This Linux forum is for members that are new to Linux.
Just starting out and have a question? If it is not in the man pages or the how-to's this is the place!

Notices


Reply
  Search this Thread
Old 12-31-2012, 05:59 AM   #31
ift38375
Member
 
Registered: Dec 2012
Posts: 32

Original Poster
Rep: Reputation: Disabled

Quote:
Originally Posted by NevemTeve View Post
> 1. If Linux providing Virtual Terminals ( Text ( 1-6) + GUI (7-12) ) then why we need to "SU" command ?

These are entirely different things. You can use 'su' both locally (/dev/ttyN) or remotely (telnet, ssh, rlogin etc). Often (for security reasons) you cannot even login as root, only login as ordinary user then 'su' to root.

> How "SU" command is differ from "SUDO" command.

Originally sudo was meant to be a safer option to delegate admin functions to users, as file /etc/sudoers controlled which user was allowed which commands. Nowadays some systems allow commands like 'sudo bash' which is equivalent to 'su' -- only you don't have to know the root password.

> Plz give me simple example so that i can easily understand at once ?

Be more precise: example for what?
Hi Nevem,

Thnaks for Reply.....

what about question 2
 
1 members found this post helpful.
Old 12-31-2012, 06:02 AM   #32
NevemTeve
Senior Member
 
Registered: Oct 2011
Location: Budapest
Distribution: Debian/GNU/Linux, AIX
Posts: 3,117

Rep: Reputation: 906Reputation: 906Reputation: 906Reputation: 906Reputation: 906Reputation: 906Reputation: 906Reputation: 906
Note: there is one thing to remember: the hardware we are talking about is PC as in Personal Computer. True, the software is multiuser/multiprocess, but the hardware is basically meant for one local user. (I repeat: the number of remote users (telnet, ssh, rlogin, X, vnc, ftp, smb, nfs, http, etc) is unlimited (meaning: limited only be the resources)).

---------- Post added 2012-12-31 at 13:03 ----------

> what about question 2

You could consider opening another topic for that.
 
Old 12-31-2012, 06:22 AM   #33
ift38375
Member
 
Registered: Dec 2012
Posts: 32

Original Poster
Rep: Reputation: Disabled
Quote:
Originally Posted by NevemTeve View Post
Note: there is one thing to remember: the hardware we are talking about is PC as in Personal Computer. True, the software is multiuser/multiprocess, but the hardware is basically meant for one local user. (I repeat: the number of remote users (telnet, ssh, rlogin, X, vnc, ftp, smb, nfs, http, etc) is unlimited (meaning: limited only be the resources)).

---------- Post added 2012-12-31 at 13:03 ----------

> what about question 2

You could consider opening another topic for that.

Hi Nevem,

I am talking about this Question:

2. If we talk about Drives or Partitions in Windows OS, then it is very simple to recognize drives like C, D, E, F.But Linux is so difficult to understand that where i will save my Work and documents Like Music, Word/Excel/Pdf file, many Stuffs. I have installed Redhat Linux ws 4 in my Computer and it is Looks like in this manner:

At desktop, there are three icons Like 1. My computer 2. Root 3.Trash
After click on " My Computer", it is showing 1. Floppy 2. Network 3. File System
After Click on "File System", it is showing some folders like 1. etc 2. bin 3. usr 3. lost-Found 4.... 5.... 6... so many

How can i create Partition in GUI mode so that i can keep Linux OS in First drive and Music in Second Drive and Documents in third Drive. ?
 
Old 12-31-2012, 06:34 AM   #34
NevemTeve
Senior Member
 
Registered: Oct 2011
Location: Budapest
Distribution: Debian/GNU/Linux, AIX
Posts: 3,117

Rep: Reputation: 906Reputation: 906Reputation: 906Reputation: 906Reputation: 906Reputation: 906Reputation: 906Reputation: 906
> I am talking about this Question:

Yes, I guessed so much.
 
Old 12-31-2012, 07:18 AM   #35
Thad E Ginataom
Member
 
Registered: Mar 2011
Distribution: Ubuntu 12.04 with KXStudio, MATE & Compiz
Posts: 46

Rep: Reputation: 7
Quote:
If we talk about Drives or Partitions in Windows OS, then it is very simple to recognize drives like C, D, E, F.But Linux is so difficult to understand that where i will save my Work and documents Like Music, Word/Excel/Pdf file, many Stuffs.
No, it is easy! --- because you do not have to know what disk or filesystem your data is on: Linux presents the whole lot to you as one tree of directories and files.

It may be a case of what you used to being "easy," "intuitive," etc. I began with Unix, and when I had to use a DOS PC I thought that all these "drives" were ridiculous and confusing. Now, I guess, I'm just used to either or both.

There is no need to justify the existence of such things as virtual terminals on the PC: they are there if you want/need them. Nobody says you have to, and I, for instance, seldom do.

Multi-user systems run software such as accounting systems, booking systems, database systems. Some of these may run in terminal software, using asci characters to draw screens; others may look more sophisticated with windows-based clients. In your home, you may have a server that will stream audio to different clients around the house. It is actually most unlikely that you have never seen *nix multi-user systems, although, of course, not all multi-user systems are Unix or Linux. This is basic Commerce as much as it is basic computing.

The thing you don't see much of, these days, is the green-screen dumb terminal. (I wonder when Wyse stopped making them?) The black rectangle with a $ prompt you see on your Windows/Linux/Etc GUI desktop is exactly the same thing done in software.

Last edited by Thad E Ginataom; 12-31-2012 at 07:23 AM.
 
Old 12-31-2012, 08:45 AM   #36
jpollard
Senior Member
 
Registered: Dec 2012
Location: Washington DC area
Distribution: Fedora, CentOS, Slackware
Posts: 4,688

Rep: Reputation: 1259Reputation: 1259Reputation: 1259Reputation: 1259Reputation: 1259Reputation: 1259Reputation: 1259Reputation: 1259Reputation: 1259
Quote:
Originally Posted by ift38375 View Post
Hi All Experts,

i have two questions:

1. If Linux providing Virtual Terminals ( Text ( 1-6) + GUI (7-12) ) then why we need to "SU" command ? How "SU" command is differ from "SUDO" command. Plz give me simple example so that i can easily understand at once ?
su is much older than virtual terminals. One use is to switch to an alternate user (not necessarily root) but maintain some context from the previous login (such as working directory).

Quote:
2. If we talk about Drives or Partitions in Windows OS, then it is very simple to recognize drives like C, D, E, F.But Linux is so difficult to understand that where i will save my Work and documents Like Music, Word/Excel/Pdf file, many Stuffs. I have installed Redhat Linux ws 4 in my Computer and it is Looks like in this manner:

At desktop, there are three icons Like 1. My computer 2. Root 3.Trash
After click on " My Computer", it is showing 1. Floppy 2. Network 3. File System
After Click on "File System", it is showing some folders like 1. etc 2. bin 3. usr 3. lost-Found 4.... 5.... 6... so many

How can i create Partition in GUI mode so that i can keep Linux OS in First drive and Music in Second Drive and Documents in third Drive. ?
Wrong way to think about things.

Directories are the organizing principle for users, not partitions.

Think about it from the point of view of multiple users... A user has a home directory, and that is organized into directories - Documents, Music, other stuff. The user login doesn't own the system, but uses it.

Now it is still possible to do division, and in many case it is done to separate the user files from system files. This is done by the administrator to specify a mount of a partition (for this purpose, usually the /home directory becomes a mountpoint). Now the system files (along with things like scratch workspace -/tmp, system logs,boot system, and most executable files...) are separate from the user files in /home. When a Linux native filesystem is mounted it has a lost+found directory created during the filesystem initialization. The mountpoint is normally owned by root, as is the lost+found directory. User files are in other directories. After mounting you the /home/lost+found, /home/user1, /home/user2... These mounts are normally controlled by the /etc/fstab file, but can also be handled by a "automount" service that does the mounts when a user logs in.

In current kernels it is possible to do exactly what you speak of, but it requires some cooperation with the system manager. The filesystems can be mounted (lets call it /documents and /music for the time being, and each of these filesystems are on separate partitions. To give the user the ability to access those filesystems the user must be given a directory on them, and given ownership of that directory. Now there are /documents/lost+found, /documents/user1 /documents/user2... and ownership of the directory user1 belongs to the user1 account.

The user can create a /home/user1/Documents using what is called a "bind mount". This is similar to the previous logical mounts on Windows. It is also possible to create a "symbolic link" to the directory.

One advantage that the bind mount has is that working directories cross logical boundaries (the bind mount point) that doesn't happen with symbolic links. The advantage symbolic links have is that they are simple, and provide information on where a data is actually stored. Bind mounts only provide that information while they exist... A symbolic link exists even if the actual pointed to target doesn't exist (as in, the partition is for some reason not mounted).
 
1 members found this post helpful.
Old 12-31-2012, 01:24 PM   #37
ift38375
Member
 
Registered: Dec 2012
Posts: 32

Original Poster
Rep: Reputation: Disabled
Hi pollard,

Why we need to Mount harddisk Partition in linux ?
is it necessary to mount the Harddisk ?
I had heard that we can mount only CD-rom, Floppy, etc
but I do not heard about mount partions.???

How to Mount Partitions in linux plz send me good URL
for this ?
 
Old 12-31-2012, 02:29 PM   #38
jpollard
Senior Member
 
Registered: Dec 2012
Location: Washington DC area
Distribution: Fedora, CentOS, Slackware
Posts: 4,688

Rep: Reputation: 1259Reputation: 1259Reputation: 1259Reputation: 1259Reputation: 1259Reputation: 1259Reputation: 1259Reputation: 1259Reputation: 1259
Quote:
Originally Posted by ift38375 View Post
Hi pollard,

Why we need to Mount harddisk Partition in linux ?
So how else does the system manager decide what partitions to use for which function, and grant user access where it is appropriate?

I have 6 partitions on 3 disks-
sda1 is my /boot partition - a fairly small partition (1GB) used for booting several different systems.

sda2, sda3 are a primary root and backup root system (~100G each).
sdc1 contains all user directories - (250GB)
sdb1 is used to hold backups (1TB)
sdb2 is held in reserve for (1TB) testing, and may be used for backup, but isn't mounted.

The advantage for me is that I can backup each partition independently of the others. Having /home on its own partition allows me to use the same user files for whichever root I happen to have running.

Quote:
is it necessary to mount the Harddisk ?
A partition/disk cannot be mounted until it has a filesystem on it. In most cases, a partition/disk must be mounted before it can be used. There are a few cases where it isn't necessary - but such cases are rare (databases sometimes access partitions directly so that they can control the caching, journaling and other capabilities) and it is usually more efficient to allow the kernel to optimize buffer handling for filesystem access.
Quote:
I had heard that we can mount only CD-rom, Floppy, etc
but I do not heard about mount partions.???
Any random access device can be used for a mount - (well, as long as there is a block interface driver for it). That means a CD/DVD/BD/Flopply/sd/... can be mounted.
Quote:
How to Mount Partitions in linux plz send me good URL
for this ?
The basic instructions are contained in the mount manpage, additional instructions for automatically mounting at boot time are contained in the man page for fstab. Options for each filesystem type are available in more manpages. You can also google for any of these topics.

How the storage space is divided up for use is up to the administrator.

Last edited by jpollard; 12-31-2012 at 02:39 PM.
 
Old 12-31-2012, 02:54 PM   #39
theNbomr
LQ 5k Club
 
Registered: Aug 2005
Distribution: OpenSuse, Fedora, Redhat, Debian
Posts: 5,397
Blog Entries: 2

Rep: Reputation: 908Reputation: 908Reputation: 908Reputation: 908Reputation: 908Reputation: 908Reputation: 908Reputation: 908
The filesystem model in Linux is that there is a single filesystem, and it is composed of one or more mounted partitions. Each partition is grafted onto the filesystem at a mountpoint. The mountpoints are chosen by the system installer, but are readily modified at runtime. There are conventions about what directories are commonly used for partition mountpoints, but these are also subject to installer modification. It is easy to mount and unmount filesystems/partitions at runtime. A very common example would be a smallish partition containing the kernel(s) and bootloader components, which would be mounted on /boot. The root ('/', not /root) directory would be another common standard as a partition mountpoint. 'Peripheral' disks such as CDs/DVDs and floppies get mounted in other somewhat standard directories, commonly under '/media'. Network filesystems (CIFS/SMB Windows shares, and NFS) get mounted according to user defined configuration.
The process of 'mounting' is what binds a partition or device or network share to the filesystem. Doing so makes it available to userspace applications. Unmounted filesystems are essentially inaccessible.
The term 'filesystem' has multiple meanings, which probably causes confusion. There is the meaning which describes the runtime system of files and directories that we see on a booted host. A discrete partition is also referred to as a filesystem in it's own right, irrespective of it status on a running host. A partition will be equipped for use by mounting it by installing a filesystem (formatting, in DOS-Windows-speak) on it. Finally, a filesystem may be what would be more accurately described as a filesystem type. There are numerous types of filesystems available to and understood by Linux, such as the ext2/ext3 classes of filesystem, the DOS-Windows filesystem types, ISO-9660 filesystems used by optical media, network filesystem types, and a host of other types. All of these usages are common, and the context of the usage generally determines which is the intended meaning.
The mount command is used to mount filesystems, and also to display which filesystems are presently mounted. The mount man page gives a good summary of the use of the command. Filesystem mounting at boot time is described in the /etc/fstab file. It describes to the system startup scripts what filesystems to mount, their mountpoints, and some respective attributes such as permissions, ownerships, and frequency of integrity testing.

--- rod.

Last edited by theNbomr; 12-31-2012 at 02:56 PM.
 
1 members found this post helpful.
Old 01-01-2013, 03:11 AM   #40
Thad E Ginataom
Member
 
Registered: Mar 2011
Distribution: Ubuntu 12.04 with KXStudio, MATE & Compiz
Posts: 46

Rep: Reputation: 7
Quote:
Originally Posted by ift38375 View Post
Hi pollard,

Why we need to Mount harddisk Partition in linux ?
is it necessary to mount the Harddisk ?
I had heard that we can mount only CD-rom, Floppy, etc
but I do not heard about mount partions.???

How to Mount Partitions in linux plz send me good URL
for this ?
You could start with man mount

This is the beginning point for all these questions.

I would suggest getting some working familiarity with the system as it is, before demanding to know "why." It's always a good question, but until you come to know the parts, it is hard to enquire about the architecture that combines them. Organic learning is good: it goes hand in hand with experience.
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off



Similar Threads
Thread Thread Starter Forum Replies Last Post
LXer: Crazies: Linux w/o Ethernet, Multi-Monitor, Multi-User LXer Syndicated Linux News 0 09-07-2012 10:51 PM
Multi-customer, multi-tenancy linux box user authentication LinuxGreen Linux - Server 2 04-27-2012 10:34 PM
Hi new user to Linux here - getting error loading operating system jthelin@csc.com Linux - Newbie 2 02-15-2009 12:28 AM
LXer: Linpus launches unique Dual-Mode User Interface Linux Operating System for Unpa LXer Syndicated Linux News 0 02-12-2008 01:30 PM
Multi-operating System Joy Stories studpenguin Linux - Newbie 18 01-05-2004 10:24 PM


All times are GMT -5. The time now is 11:12 PM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration