what exactly happens when i mount a fat32 partition on ext3?

is the partition actually "mounted" and takes up the space on ext3?
OR
is the partition just read from where it is?

for example if i have given 25 gb to ext3 and i try to mount 30 gb of fat32 on it will it be mounted?

also is it possible to mount ntfs? can someone give me the command.

When you mount partitions, they will not take up space from the partition you mount them to. Mount works for both FAT32 and NTFS, but to have read and write access to NTFS you must compile NTFS support into the kernel.

I think you've got things a bit tangled here (if that's the right word...). Could you give (as user root ('#' is root shell prompt)) the result of:
As for NTFS, you'll only have read-only access, unless you use the "Captive" driver; I have never used this so I can't help with ntfs.

Yves.

Think of the command "mount" as putting a tape on a tape drive so the system can read and write to it.

When you mount a fat32 partition, it is added into the existing file system at some mount point you specify.

The concept in Linux is different to other OS's like windows. Everything starts at the root, designated by the "/" If you add a directory, it is referenced from the root. ie. /home/user is where your user stuff goes. Note the "/" at the beginning. This says root.

Partitions are simply mounted to some point; either from the root, or through some directory structure. There is is difference in that linux doesn't reference hard drives as windows does, and that doesn't show up in the single tree structure.

So to answer one question, mounting a fat32 has nothing to do with the ext3 partitions you have or the ext3 size.

The basic thing you have to do is create a directory in the existing file system where you want to mount the new partition. Most linux distro's have a directory /mnt. This is a place you can mount more partitions if they are to be used by the system, or local users. If at any point you want to share files on this partition through samba, ( windows shares) you need to mount it within a home directory.

As for the mount command, it is much easier to add the command to your /etc/fstab file and have it mounted at boot time. Here is a sample of a fat32 partition I have mounted.

/dev/hda1 /mnt/win_c vfat umask=0,iocharset=iso8859-15,codepage=850 0 0

The first part /dev/hda1 is the hard drive and partition I'm mounting. The /mnt/win_c is the mount point I'm specifying. I had to run a command "md" make dir once to create an empty directory. The rest of the stuff tells linux what file system (vfat) character set etc to expect. Fstab is read during the boot process, and a mount command is done for each partition.

Hope this helps.

MOUNTING=====NTFS
#mkdir /mnt/ntdrive
= look which is your NTFS drive eg /dev/hda5
#mount /dev/hda5 /mnt/ntdrive -t ntfs -r -o umask=0222
= ntfs kernel must be installed find in sourceforge must same kernel use using

MOUNTING=====FAT
#mkdir /mnt/fatdrive
= look which is your fat drive . eg. /dev/hda6
#mount -t vfat /dev/hda6 /mnt/fatdrive

have fun

thanks a lot guys.... appreciate the great answers! thanks camorri for the detailed answer!