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Old 07-13-2008, 05:51 AM   #1
Registered: Jan 2007
Location: Scotland
Distribution: Fedora, Debian
Posts: 81

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how does this work in unix?

hi, just some questions from a wannabe linux/unix guru.

ive just discovered what fstab is for:
defining where things are to be mounted upon startup(correct?)
it also defines what drive is mounted to /.

this is where I am confused. how does this file get read, if it resides in /? (/ being a mountpoint that IT defines)

I am reminded of a curiosity about minix i have:
It says that in minix, the memory management runs as a user process.
How do you start this process if there is no memory manager active?????? Wouldnt the memory manager need to have it's memory a memory manager??

also, what are these files:

I think they are for starting programs, setting variables when a user logs in. if this is the case, why are there two of them?

These things have been bugging me for some time, can somebody please shed some light on the above?

Old 07-13-2008, 06:07 AM   #2
Senior Member
Registered: Aug 2004
Location: England
Distribution: Ubuntu
Posts: 1,039

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ftsab doesn't just say what filesystems are mounted where, it also says what filesystem options are used.

When booting (either using GRUB or LILO) the system is told where to find the boot partition so that it can read the ftsab file and perform a complete boot (after all, the startup scripts are also located on /).

As a part of the boot process, the fstab file is read and then / is remounted (along with all the other partitions) using the mount options specified in /etc/fstab.

I hope this clarifys things for you.
Old 07-13-2008, 08:27 AM   #3
Registered: Mar 2008
Location: Baltimore Md
Distribution: ubuntu
Posts: 184

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You are right about the bash files, they set variables and various other things. The reason for 2 files is that .bash_profile is read only when logging in; .bashrc is read whenever a shell is started, for instance when opening a terminal.
Old 07-13-2008, 09:42 PM   #4
Registered: Feb 2008
Distribution: Debian Testing, OSX
Posts: 164

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That is right. The filesystems are mounting read only to start. Once the appropriate files are read, (fstab in this case), the filesystems are mounted with the proper options in place. If you read through all the boot messages carefully, you will see one which says something like "mounted root filesystem read only" and then a little later one which says it has been mounted read/write.


bash, fstab, mounting, process

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