8. Linux Configuration

These instructions cover setting up the virtual RAID drives on RedHat Linux 6.1. Setting it up under other Linux distributions should not be a problem. The same general instructions apply.

If you are new to Linux you may want to consider installing Linux from scratch since the RedHat installer will do most of the configuration work for you. If so skip to section titled "New Linux Installation." Otherwise go to the "Existing Linux Installation" section (next).

8.1 Existing Linux Installation

Follow these instructions if you already have Redhat Linux installed on your system and you do not want to re-install. If you are installing the RAID as part of a new RedHat Linux installation (or are re-installing) skip to the "New Linux Installation" section.

QLogic SCSI Driver

The driver can either be loaded as a module or compiled into your kernel. If you want to boot from the RAID then you may want to use a kernel with compiled in QLogic support (see the kernel-HOWTO available from http://www.linuxdoc.org. To use the modular driver become the superuser and add the following lines to /etc/conf.modules:

alias qlogicpti /lib/modules/preferred/scsi/qlogicpti 

Change the above path to where ever your SCSI modules live. Then add the following line to you /etc/fstab (with the appropriate changes for device and mount point, see the fstab man page if you are unsure)

/dev/sdc1 /home ext2 defaults 1 2

Or, if you prefer to use a SYSV initialization script, create a file called "raid" in the /etc/rc.d/init.d directory with the following contents (NOTE: while there are a few good reasons to start the RAID using a script, one of the aforementioned methods would be preferable):

#!/bin/bash

case "$1" in

start)

echo "Loading raid module"

/sbin/modprobe qlogicpti

echo

echo "Checking and Mounting raid volumes..."

mount -t ext2 -o check /dev/sdc1 /home

touch /var/lock/subsys/raid

;;

stop)

echo "Unmounting raid volumes"

umount /home

echo "Removing raid module(s)"

/sbin/rmmod qlogicpti

rm -f /var/lock/subsys/raid

echo

;;

restart)

$0 stop 

$0 start 

;; 

*)

echo "Usage: raid {start|stop|restart}"

exit 1

esac

exit 0 

You will need to edit this example and substitute your device name(s) in place of /dev/sdc1 and mount point(s) in place of /home. The next step is to make the script executable by root by doing:

chmod 0700 /etc/rc.d/init.d/raid

Now use your run level editor of choice (tksysv, ksysv, etc.) to add the script to the appropriate run level.

Device mappings

Linux uses dynamic device mappings you can determine if the drives were found by typing:

more /proc/scsi/scsi

one or more of the entries should look something like this:

Host: scsi1 Channel: 00 Id: 00 Lun: 00 

Vendor: ANTARES Model: CX106 Rev: 0109

Type: Direct-Access ANSI SCSI revision: 02

There may also be one which looks like this:

Host: scsi1 Channel: 00 Id: 00 Lun: 07

Vendor: ANTARES Model: CX106-SMON Rev: 0109

Type: Direct-Access ANSI SCSI revision: 02

This is the SCSI monitor communications channel which is currently un-used under Linux (see SMON in the advanced topics section below).

To locate the drives (following reboot) type:

dmesg | more

Locate the section of the boot messages pertaining to you SCSI devices. You should see something like this:

qpti0: IRQ 53 SCSI ID 7 (Firmware v1.31.32)(Firmware 1.25 96/10/15) 

[Ultra Wide, using single ended interface]

QPTI: Total of 1 PTI Qlogic/ISP hosts found, 1 actually in use.

scsi1 : PTI Qlogic,ISP SBUS SCSI irq 53 regs at fd018000 PROM node ffd746e0
 

Which indicates that the SCSI controller was properly recognized, Below this look for the disk section:

Vendor ANTARES Model: CX106 Rev: 0109

Type: Direct-Access ANSI SCSI revision: 02

Detected scsi disk sdc at scsi1, channel 0, id 0, lun 0

SCSI device sdc: hdwr sector= 512 bytes. Sectors= 20971200 [10239
 MB] [10.2 GB]

Note the line that reads "Detected scsi disk sdc ..." this tells you that this virtual disk has been mapped to device /dev/sdc. Following partitioning the first partition will be /dev/sdc1, the second will be /dev/sdc2, etc. There should be one of the above disk sections for each virtual disk that was detected. There may also be an entry like the following:

Vendor ANTARES Model: CX106-SMON Rev: 0109

Type: Direct-Access ANSI SCSI revision: 02

Detected scsi disk sdd at scsi1, channel 0, id 0, lun 7

SCSI device sdd: hdwr sector= 512 bytes. Sectors= 20971200 [128 MB]
 [128.2 MB]

BEWARE: this is not a drive DO NOT try to fdisk, mkfs, or mount it!! Doing so WILL hang your system.

Partitioning

A virtual drive appears to the host operating system as a large but otherwise ordinary SCSI drive. Partitioning is performed using fdisk or your favorite utility. You will have to give the virtual drive a disk label when fdisk is started. Using the choice "Custom with autoprobed defaults" seems to work well. See the man page for the given utility for details.

Installing a filesystem

Installing a filesystem is no different from any other SCSI drive:

mkfs -t <filesystem_type> /dev/<device>

for example:

mkfs -t ext2 /dev/sdc1

Mounting

If QLogic SCSI support is compiled into you kernel OR you are loading the "qlogicpti" module at boot from /etc/conf.modules then add the following line(s) to the /etc/fstab:

/dev/<device> <mount point> ext2 defaults 1 1

If you are using a SystemV initialization script to load/unload the module you must mount/unmount the drives there as well. See the example script above.

8.2 New Linux Installation

This is the easiest way to install the RAID since the RedHat installer program will do most of the work for you.

1. Configure the host port, RAID sets, and spares as outlined in "Onboard Configuration." Your computer must be on to perform this step since the 5070 is powered from the SBUS. It does not matter if the computer has an operating system installed at this point all we need is power to the controller card.
2. Begin the RedHat SparcLinux installation
3. The installation program will auto detect the 5070 controller and load the Qlogic driver
4. Your virtual RAID drives will appear as ordinary SCSI hard drives to be partitioned and formatted during the installation. NOTE: When using the graphical partitioning utility during the RedHat installation DO NOT designate any partition on the virtual drives as type RAID since they are already hardware managed virtual RAID drives. The RAID selection on the partitioning utilities screen is for setting up a software RAID. IMPORTANT NOTE: you may see a small SCSI drive ( usually ~128 MB) on the list of available drives. DO NOT select this drive for use. It is the SMON communication channel NOT a drive. If setup tries to use it it will hang the installer.
5. Thats it, the installation program takes care of everything else !!