I have 2 ide hard drives (Master + Slave). How can I load up /dev/hdb automatically at start up.


2nd question - Redhat installs a directory called /opt. How do I get more information about it.
such as:
- Which /dev/hd? it's on
- What it's capacity is
- and so on...

I can answer only the first part of the question.

You have to modify your /etc/fstab (under root priveliges) and append the partition names and device
names and their file systems.
e.g. /dev/hdb1 /mnt/<2nd harddisk first partition> vfat

(replace the names appropriately) and only with these three entries. There are other options but I
think you need not specify anything there.

How can I load up /dev/hdb automatically at start up.
Add a line in your /etc/fstab to have it mount at a specific mount point.


2nd question - Redhat installs a directory called /opt. How do I get more information about it.
such as:
- Which /dev/hd? it's on
- What it's capacity is
- and so on...

The command mount will tell you what directories are mounted on which devices. df -hT will tell you the device, total disc space, free space, filesystem, and mount point. Odds are that /opt is not specifically mounted on its own partition, it is probably on the same partition as /

If you want to know how much space opt is taking up, you could type du --max-depth=1 / that will tell you how much space each directory under / take up.

/opt is for installing additional software packages after the installation. In most cases it will be empty. /opt is not typically on its own partition so therefore it will be part of your / (root partition).

The default Redhat installation creates 3 partitions and I will assume the entire OS installation is on one drive. / (root partition), /boot and swap partitions. /boot contains the kernel and other files required to boot the system. The size is typically 50-100 mb. The swap partition is like windows virtual memory and it is typically 2x RAM size. The rest of the drive will be your / partition and all directories except /boot will be included.

The output of the following command will show the size of all mounted filesystems.
df -h

To see how the drive is partitioned use the following command (requires root login):
fdisk -l

Here is a good basic tutorial.
http://www.icon.co.za/~psheer/book/index.html.gz

Thank you all for the replies. Great info.