1. Introduction

The goal of this HOWTO document is to explain how to setup RAID 1 (mirroring) with the two hard disks and install bootable RedHat Linux Operating System on the mirror device. This document discusses both methods of achieving this goal: 1. Using Promise supplied driver 2. Using Linux native RAID. If you choose the first method (using Promise supplied driver), you must use the Kernel 2.4.7-10 that comes with RedHat 7.2 CD. If you choose the second method, you can upgrade the kernel to the latest kernel (2.4.18). This document does not discuss Striping or other disk configurations, although the author believes that this document might help setup those configurations. This document does not yet cover: 1. Installation using GRUB instead of LILO and 2. Installation with Latest development kernels (2.5.x).

First of all we need a bit of legalese. Recent development shows it is quite important.

2. Requirements

This section lists what items are required before you start installing on your computer.

• Two blank floppies, DOS formatted. On a working linux computer, you can type mkfs.msdos /dev/fd0

• Red Hat Linux 7.2 CDs 1 and 2 (3 and 4 contain SRPMS and are not required)

• Internet connection available

• Your computer with working CD, floppy,10/100 ethernet card support

• Patience

3. Prepare Promise Driver Floppy

1. Download appropriate driver from one of the two sites below and save the driver on one of the blank floppies. You can do this on any computer connected to Internet.

   • Driver for Single Processor Machine

   • Driver for Multiple Processor Machine

2. Insert the floppy with the driver tar ball into a working Linux computer and type:

   mount /dev/fd0 /mnt/floppy cd /mnt/floppy cp rhsmp-ft12014.tgz /tmp tar xvzf /tmp/rhsmp-ft12014.tgz cd / umount /mnt/floppy

3. Label the floppy »Promise FastTrack driver« and set it aside.

4. Preparing RedHat 7.2 CDs

	NOTE
	If you already have Red Hat Linux 7.2 CDs 1 and 2, skip this step. Otherwise, read this step to learn how you can get them for free.

1. Logon to a Windows computer that has a CD Writer drive installed and setup properly. Insert a blank CD-R into the CD Writer.

2. Point your browser to the Red Hat Web site: ftp://ftp.redhat.com/pub/redhat/linux/7.2/en/iso/i386/.

3. Browse and locate enigma-disc1.iso (the first disk of Red Hat 7.2), and save this file to your Windows desktop.

4. Right-click on the iso image created on your desktop and choose "Record to CD" It will then write the iso image onto your CD-R and create disk-1.

5. Repeat the procedure for the second iso file named enigma-disc2.iso on ftp.redhat.com/pub.

6. Test to make sure your CD-Rs are indeed readable. If you click on »My Computer« and click on the CD Writer Drive icon, you should be able to browse the contents of the CD-R.

7. Label the CD-Rs properly: RH 7.2 disk-1 and RH 7.2 disk-2

5. Installing Red Hat 7.2

Once you have created your CDs, you are ready to begin installing Red Hat 7.2 on your Linux system.

1. Restart the computer and press Cntrl-F when you see FastTrack BIOS prompt on screen. This will take you into the Promise FastTrack BIOS.

2. Inside this BIOS, choose "delete array," "define array," and "choose Mirror."

3. Press Cntrl-Y to save.

4. Choose »Create Only« and ESC to reboot. When it reboots, you should see that Promise FastTrack now has 1x2 RAID Mirror defined over your two hard disks connected to FastTrack controller.

5. Insert your Red Hat 7.2, disk-1 into your CD-ROM and reboot.

6. At the boot-prompt, type:

   linux noprobe

7. Now, installation will begin. Choose »Add device« and scroll through the list of available drivers to see if Promise FastTrack is listed. If it is not listed, press F2 to load external driver from a floppy. Insert your Promise FastTrack driver floppy and hit "OK."

8. Continue with installation. Choose only ext3 type partitions for now. You can make ext2 partions at the very end, if you really need them.

9. When the system you to create Boot Floppy, insert a blank floppy disk. The Red Hat installation program will create a Boot Floppy disk.

   	NOTE
   	Please do not click on »Skip boot disk creation«. If you skip this step and do not create a Boot Floppy disk, you will be very sorry later.

10. When the install asks you to choose Boot loader configuration, please choose »LILO only«. Do not choose »GRUB« as your boot loader.

    When the installation is finished, you will see »Congratulations« screen.

11. Press Cntrl-ALT-F2 to switch to tty2.

12. At the shell prompt, type:

    cd /mnt/sysimage/lib/modules/2.4.7-10/kernel/drivers/scsi

13. Type ls and make sure the file ft.o exists. If not, you are going to need to manually install the module ft.o as follows:

    1. Make sure your Driver floppy is mounted. Go into the floppy and type

       mv module.cgz /tmp cd /tmp gzip -dc module.cgz | cpio -idumv

    2. Now, you will see a bunch of directories created under /tmp.

       cd /tmp/`uname -r` cp ft.o /mnt/sysimage/lib/modules/`uname -r`/kernel/drivers/scsi

    3. At the shell prompt, type:

       less /mnt/sysimage/etc/lilo.conf

       Check to see that the lilo.conf looks good. Especially, it should have the initrd= line and the corresponding initrd.img file must exist in /mnt/sysimage/boot. If not, you are going to create it manually as follows:

       /mnt/sysimage/usr/sbin/chroot /mnt/sysimage /sbin/mkinitrd \ --preload jbd \ --preload ext3 \ --preload scsi_mod \ --with ft \ /boot/initrd.img 2.4.7-10

14. Now, remove the floppy and the CD, and reboot. At this point, pray that your computer will boot without any problems.

15. If it does not boot, insert your Boot Floppy and reboot and login; And then repair as follows:

    1. Make sure /boot/initrd.img exists. Make sure /lib/modules/2.4.7-10/kernel/drivers/scsi/ft.o exists (If not you have to manually fix these issues as explained above)

    2. Type: /sbin/lilo

    3. Now, remove floppy and reboot. Your machine should boot into your new machine now using Promise Driver.

16. Type df -k and you should see your hard disks as /dev/sdaX instead of /dev/hdaX. This is because the Promise Driver is actually a special type of Software Emulation RAID, not exactly Hardware RAID. (Promise RAID works through a BIOS Hack).

1. When you boot your machine into 2.4.7-10 uniprocessor kernel, type the following to make initrdsmp.img to be used for 2.4.7-10smp kernel:

   /sbin/mkinitrd \ --preload jbd \ --preload ext3 \ --preload scsi_mod \ --with ft \ /boot/initrdsmp.img 2.4.7-10smp

   	NOTE
   	If you are tired of remembering the command to create initrd files, dowload my geninitrd script and keep it handy.

2. Adjust your /etc/lilo.conf accordingly for 2.4.7-10smp (the SMP kernel section), type /sbin/lilo and reboot into the SMP kernel. Here is how /etc/lilo.conf should look like.

At this point, you have a working Red Hat 7.2 machine with SMP support, if applicable. If you are happy with the fact that you are running a fake Hardware RAID from Promise FastTrack using SCSI Emulation, then read no further.

Because Promise Driver is a SCSI emulation, it puts a lot of load on CPU(s). Read on if you want to enable true Linux native RAID and get rid of this Promise SCSI emulation.

6. Installing Native Linux RAID

The first step you want to take is to configure your networking and connect your computer to Internet, which is still running under Promise Driver SCSI emulation. Next you will install native Linux RAID.

1. Go to www.kernel.org and download latest kernel 2.4.18.tar.gz.

2. Configure your kernel:

   cd /usr/src/ tar xvzf linux-2.4.18.tar.gz cd linux # cd to kernel source directory just created by tar cp config.txt .config #(See NOTE below to find out where to get config.txt) make menuconfig

   	NOTE
   	You can download a working config.txt file HERE. You can, of course, modify this to suit your needs either directly in a text editor or by typing make menuconfig as explained above. It is easy to make mistakes if you are editing .config directly in vi or emacs. Therefore, it is recommended to use Menu Interface by typing make menuconfig.

3. Enable all the following in the kernel statically (NOT as modules):

   ATA/IDE/MFM/RLL Support --> <*> ATA/IDE/MFM/RLL Support IDE/ATA/ATAPI Block Devices --> <*> Enhanced ATA/IDE/MFM/RLL disk/cdrom/tape/floppy support <*> Include IDE/ATA-2 Disk Support [*] Use multi-mode by default Include IDE/ATAPI CDROM support [*] Generic PCI IDE chipset support [*] Sharing PCI IDE interrupt support [*] Generic PCI Bus master DMA support [*] Use PCI DMA by default when available [*] Intel PIIXn chipset support [*] PIIXn tuning support [*] Promise PDC202{46|62|65|67|68} support [*] Special UDMA Feature [*] Special FastTrack Feature [*] VIA 82CXXX chipset support <*> Support for IDE RAID controllers <*> Support Promise Software RAID (fasttrack)

4. After you have enabled static features as shown above, make any more changes that you would like to make to suit your environment.

5. Save the kernel configuration. It is saved to .config in the current directory. Please back up this file. If you dont do so, you will regret it later. Copy .config file in a blank floppy or in /root

6. Build and install the kernel like you normally do, by typing:

   make dep ; make clean ; make && make install make modules && make modules_install

Look at /etc/lilo.conf to make sure new lines are added to boot your new kernel 2.4.18. Note that there should not be an initrd= line for this new kernel in /etc/lilo.conf. That is, our new kernel will boot itself without depending on a initrd.img unlike your current 2.4.7-10 kernel.

Now adjust /etc/lilo.conf as follows:

1. Locate the root=/dev/sdaX line for the new kernel in /etc/lilo.conf. Change this to root=/dev/ataraid/d0pX where X is a number 1 through 16. Save your changes.

2. Type:

   /sbin/lilo

3. If you chose any ext2 partitions during installation, you should comment them out in /etc/fstab for now.(Best thing is: Forget ext2 in this whole process)

4. Remove all floppies and CDs, and reboot by typing:

   sync;sync;reboot

5. At the LILO prompt, type your new kernel lable corresponding to 2.4.18 Your computer should then boot into your new kernel.

6. Login and type df -k to make sure you see /dev/ataraid/d0X entries instead of earlier /dev/sdaX entries.

   	NOTE
   	You may see some errors related to mounting swap device at the time of booting into new kernel. These are harmless. You should edit /etc/fstab to change any sdaX entries to ataraid/d0pX entries.

7. Now, connect your computer to Internet and download lilo-22.tar.gz (the latest version of lilo program) from the Internet.

8. Remove the existing lilo on your computer by typing: rpm -e --nodeps lilo

9. Install new version of lilo as follows:

   tar xvzf lilo-22.tar.gz cd lilo-22 # cd to lilo source directory just created by tar ./QuickInst.sh

10. Say "Yes" to questions the system will ask you.

11. Ignore any errors except if /sbin/lilo is not created.

12. Adjust /etc/lilo.conf as follows:

    • Replace linear by lba32

    • Delete line "compact"

    • Change vga= line to vga=normal

    • Change boot=/dev/sda line to boot=/dev/ataraid/dN (where N is the partition number on which your root file system exists. Type df -k / to find out your root partition number).

    • Make sure that default=linux-2.4.18 (where linux-2.4.18 is the label given to boot your new kernel: 2.4.18)

13. Save changes to the file and type: /sbin/lilo

14. Reboot the system and cross your fingers.

Here is how the final /etc/lilo.conf should look like.

If everything comes up without any errors, time to celebrate!!

7. Installing on an existing Linux system

This section explains how to install Linux Native ATA RAID on non-OS disks you may have on a running Linux machine. Non-OS disks are those which do not contain any Linux OS partitions such as /, /usr, /var, /boot. In other words, we have a working Linux machine with two free disks and we want to setup ATA RAID mirror (raid 1) on those two disks. When we save important data on such a mirror device, our data is protected. Ofcourse, like any other RAID 1, we will experience improved read speeds while reading the data and slightly decreased write speeds while modifying or adding new data to the mirror device. Therefore, using RAID 1 for data disks is recommended if the data disk is more frequently read than written to. A web server hosting rarely changing web sites is a good example where web content is rarely modified but very frequently accessed by users.

Here are the steps to install non-OS ATA RAID if your RAID chip is from Promise Technology:

• Find out IO address numbers and IRQ number(s) for your Promise RAID chip/card.

• Edit /etc/lilo.conf and insert appropriate Append Line

• Enable ataraid support either by automatically loading ataraid module when your Linux machine starts up or by statically building ataraid support into your kernel

8. Upgrading Kernel

Read this section carefully before you plan to upgrade kernel on your Linux machine with Promise FastTrack RAID. Unless you are not using Promise FastTrack at all in any way, you need this information to avoid problems.

Always backup your data before kernel upgrade. Also backup /etc/fstab, /etc/lilo.conf, /boot/vmlinuz-currentversion and /boot/initrd.img (if you use initrd). When you upgrade your kernel, do not delete old kernel or its dependent files in /boot and do not delete the lines corresponding to it in /etc/lilo.conf. If you upgrade kernel to say 2.4.19, just create another kernel section in /etc/lilo.conf. For example, add the following lines to /etc/lilo.conf:

# Begin Code for booting my brand new kernel: 2.4.19 image=/boot/vmlinuz-2.4.19 label=linux-new read-only root=/dev/ataraid/d0p12 # End Code for booting my brand new kernel: 2.4.19

Also, do not change default=linux line in /etc/lilo.conf unless and until you successfully can boot into your new kernel by typing linux-new at the boot: prompt (or highlighting linux-new in the menu, if you are using LILO in curses menu mode).

Now lets discuss the actual process of upgrading kernel in the following four cases:

1. Promise Technology (ft) Driver with OS on RAID mirror

2. Promise Technology (ft) Driver with non-OS data on RAID mirror

3. Linux Native (ataraid) Driver with OS on RAID mirror

4. Linux Native (ataraid) Driver with non-OS data on RAID mirror

OS stands for "Operating System" or more specifically Red Hat Linux Operating System in our case. When you install Linux on mirrored partitions such as /dev/ataraid/d0p1 (or /dev/sda1 when using Promise Technology proprietary driver), you are said to have your OS on RAID mirror. If your Linux machine has only the main partitions such as / and /boot on RAID, it is also called (a case of) OS on RAID.

Partitions created by user to make use of available free partitions such as /mydata1, /imp, /scratch are not part of Linux OS because Linux does not install any files into them by default when you install Linux or upgrade any standard Linux software package. Any data in such user partitions becomes user data or alternatively, non-OS data. It is a good idea to use only ext3 and swap file systems for OS partitions. For non-OS partitions, you can use other file systems such as ext2 and dos (if you have another operating system like Windows on the same Linux computer or if you just feel like you love dos so much). However, why do you want to use ext2 if you dont have to and you have a better choice of using ext3 for OS or non-OS partitions?

9. Disabling RAID feature on Promise FastTrack

If you are reading this section, then you may be sick and tired of the fake RAID feature (formally known as quasi-hardware RAID) provided by Promise Technology FastTrack card or onboard chip on your motherboard.

10. Tips and Important Notes

• Dont bother using KDE / GNOME or any other X window system to finish RAID installation as explained above. Use simple text terminal.

• You can press Cntrl-ALT-Fj to switch to ttyj where j=1,2,..6

• If you do start KDE/GNOME or any other X window system, it will run on tty7, which you can access by pressing Cntrl-ALT-F7

• If you decide to use Promise supplied SCSI emulation driver for FastTrack RAID, note that you are stuck at the default kernel version 2.4.7-10. Because, no source code for FastTrack is available.

• During RH 7.2 installation, choose ext3 and swap file types only.

• When you remove Promise SCSI emulation and setup Native Linux RAID, linux lets you access the hard disks either by mirror name: d0 or individual disks themselves: hde2, hdg3 etc. It is very important that: YOU NEVER access the hard disks directly by their name, instead access the corresponding mirror partition. Example: Use /dev/ataraid/d0p3 instead of /dev/hde3 or /dev/hdg3

11. For more information

For more information, please check the following resources

• Quasi-Mini-HowTo at http://www.geocities.com/ender7007/

• LhD Product Page at http://lhd.datapower.com/db/dispproduct.cgi?DISP?2751. You can also go to LhD Main Page and search for »Promise FastTrack«.

• ATA RAID help document by RedHat, Inc. You can also join their ataraid mailing list, or atleast search the mailing list archive.

• Promise Technology's support web site at http://support.promise.com. Also check out this page.

• Promise FastTrack help for Linux Mandrake is available at http://www.magic-lamp.org.