problem detect hard drive

[mandrakelinux]

i've added additional hard drive to my system (mandrake)but it doesn't appear .

i tried to see if my hard exist in patitions at control center but when clicked patitions icon i got this message (i can't read the partition table of device hdb it's too corrupted for me i can go on erasing over bad partions . the solution is to not allow drakx to modifa the partition table )

[drakebasher]

First thing I would do is verify that Linux recognizes the drive correctly. You can do this with the fdisk command, but you must have root privleges to do it:

$  su -
(enter password when asked)
#  fdisk -l | less

Use up/down arrow keys to scroll through the output and press q to exit from "less". With fdisk, you should see each hard drive in your system, it's size and all of the partitions and partition types. Once you have confirmed that Linux recognizes the drive correctly, you should be able to run fsck which will check and repair the filesystem on the drive. Read the manual page for fsck ($ man fsck). fsck should be run on filesystems which are not mounted. After running fsck, the filesystem can be mounted (read the 'mount' manual page) and then read same as any other filesystem.

[mandrakelinux]

thanks drakebasher
i can see my two hards in fdisk but can't see the second hard in fstab file

[drakebasher]

i can see my two hards in fdisk but can't see the second hard in fstab file

fstab is a file that tells your Linux what filesystems to mount. A filesystem must be mounted before you can read it. It may be mounted manually with the 'mount' command or it may be mounted automatically if it is entered in fstab.

So, to read the drive, you should be able to do:

mount /dev/hdb1 /mnt
...or...
mount /dev/hdb1 /home/yourusername

You must have super user privleges to do that: either log in as root or (better) 'su -' to become super user. When you run 'fdisk -l', you will see what partitions are on the drive: hdb1, hdb2, etc. and you will see what type of filesystem it is: Linux, vfat, swap, extended... If Linux says that it needs to be told what filesystem type the drive is, the filesystem is probably corrupted or is a type that cannot be mounted. Swap partitions cannot be mounted the same way as others. The partition (there's maximum one per drive) of type "extended" cannot be mounted because it is just a "container" for holding all partitions with a number greater than 4 (hdb5, etc). If 'fdisk -l' says the partition is type 'Linux' but Linux says it needs to know the type of filesystem when you try to mount it, that's a clue that the filesystem is corrupted and you need to run fsck (see previous post).

[mandrakelinux]

thanks a lot
i mounted hdb
but i still have 2 questions
1- how can i automate mount at start up ?
2- could i make a new partition and formate it from control
center--->partition and formate it (any type of formate especially vfat)

[drakebasher]

Mounting will be automatic if you add a line in your file /etc/fstab for that partition. Take a look at that file and look at how your other filesystems are entered. The format of the additional line will be something like:

/dev/hdb1 /home/newdrive ext2 defaults 1 2

Where:

• '/dev/hdb1' should be the correct identification of your new partition or drive (do 'fdisk -l' to see that)
  '/home/newdrive' should be the mountpoint where you want to mount it. The mount point must exist (do 'mkdir /home/newdrive').
  For the other stuff, follow the format of your other mounted hard drive partitions.

Post your /etc/fstab (or parts of it) if you need more help.

2. Not sure about formatting hard drive partitions that way. I know you can do floppies. Try it out!

[mandrakelinux]

many thanks drakebasher
really it works good i'm happy . but i wanna ask one question
does reboot command destroy system (does't work any more) or at least corrupt filesystem table ?

[drakebasher]

does reboot command destroy system (does't work any more) or at least corrupt filesystem table ?

No.... man, questions like that make me nervous. The reboot command should cause an "orderly" shutdown and restart. That means that it should go through an init script same as for a normal shutdown, followed by restart. Is this a question of curiosity or do you have a problem? I should have mentioned previously that when you add lines to the /etc/fstab file, they usually should be added at the end. The sequence of mounting essential filesystems is important and mounting of non-essential filesystems should occur after all essential ones.

As to a "corrrupt filesystem table", I know that some distros use means of automatically modifying the fstab file. Fedora Core 3 is one. I'm not a fan of that idea, but I'm not familiar with the details.

[mandrakelinux]

i used to use shutdown -r to restart the machine but once i've typed reboot after i mounted my two hard drives , two hard has gone ( no filesystem , no partitions , nothing at all ) all i've seen is two blank

[drakebasher]

I don't understand this:

all i've seen is two blank

What do you mean?

If you do:

fdisk -l /dev/hdb

(where I'm assuming that "hdb" is the drive that you are unable to see) what is the result?

In a previous post, you asked about formatting partitions. Did you try to format a partition, and if so, what did you do?

shutdown -r is equivalent to reboot