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Linux IDE-RAID Notes - SCSI-S18RAID

August 2000

# df -h /mnt/tmp
Filesystem               Size     Used    Avail     Use% Mounted on
/dev/md0                 167G     0.0G     167G     100% /mnt/tmp

Hardware

Tyan Tiger100 with 2 Pentium II 400MHz
Adaptec 2940U2W - Ultra2W SCSI controller (80MB/s)
11 Seagate Barracuda 18 - 18GB SCSI ST118273W/LW 7200RPM 7.9ms (16MB/s)
1 Western Digital Caviar 5400 - 10.2GB EIDE Ultra-ATA/66 5400RPM 9.5ms (29MB/s) [boot drive]
 
SCSI id drive interface
0 LW Fast/Ultra-SE
1 LW Fast/Ultra-SE
2 W Fast/Ultra-SE
3 W Fast/Ultra-SE
4 W Fast/Ultra-SE
5 W Fast/Ultra-SE
6 W(term) Fast/Ultra-SE
8 LW ULTRA2-LVD
9 LW ULTRA2-LVD
10 LW ULTRA2-LVD
11 LW ULTRA2-LVD

The mix of 6 LW and 5 W drives has 4 LW on the Ultra2-LVD/SE bus and the remaining drives on the UltraW bus.  This is not optimal, but is what is possible with the cables on hand, and given the lowest common denominator of UltraW, it is probably adequate.  Yes, this is SCSI and not IDE, but I was given the parts, and I put it here for comparison. I'm considering the addition of second Adaptec 2940U2W SCSI controller for more SCSI-bus bandwidth.

Software

RedHat 6.2 Linux 2.2.14 kernel

Linux 2.2.x kernel /usr/src/linux-2.2.x - Kernel-HOWTO

ide.2.2.14.20000124.patch.gz

http://www.kernel.org/pub/linux/kernel/people/hedrick/ - ide patches, including Promise

Log

# umask 002
# mkdir /usr/src/linux-2.2.14-ide
# rm /usr/src/linux
# ln -s /usr/src/linux-2.2.14-ide /usr/src/linux
# cd /usr/src/linux-2.2.14
# find . -print | cpio -pdumv ../linux-2.2.14-ide
# cd ../linux-2.2.14-ide
download and uncompress ide.2.2.14.20000124.patch
# patch -p1 < ide.2.2.14.20000124.patch > patch.out
IMPORTANT - edit the FAILED hunks by hand
# make mrproper
# make xconfig
        make xconfig
            SCSI low-level drivers
            y            Adaptec AIC7xxx support
# make dep clean bzImage modules modules_install
# sh scripts/MAKEDEV.ide
# cp arch/i386/boot/bzImage /boot/vmlinuz-2.2.14-ide
# cp System.map /boot/System.map-2.2.14-ide
# ed /etc/lilo.conf
image=/boot/vmlinuz-2.2.14-ide
    label=linux-ide
    initrd=/boot/initrd-2.2.14-5.0.img
    read-only
    root=/dev/hda5
# lilo    # LILO mini-HOWTO, BootPrompt-HowTo
# reboot
lilo: linux-ide

Disk Configuration

Standard ext2fs setup/test example

    # cfdisk /dev/hde
    # hdparm -Tt /dev/hde # repeat several times
    # mke2fs /dev/hde1
    # mount -t ext2 /dev/hde1 /mnt/tmp
    # cd /mnt/tmp
    # Bonnie -s 500 -html -m hde
    # cd /
    # umount /mnt/tmp

RAID setup/test example

    # cfdisk /dev/hde # make partitions
    # ed /etc/raidtab # see http://ostenfeld.dk/~jakob/Software-RAID.HOWTO/
    # mkraid /dev/md0
    # cat /proc/mdstat
    # hdparm -Tt /dev/md0 # repeat several times
    # mke2fs -m0 /dev/md0
    # mount -t ext2 /dev/md0 /mnt/tmp
    # cd /mnt/tmp
    # Bonnie -s 500 -html -m md0
    # cd /
    # umount /mnt/tmp
    # raidstop /dev/md0

NoBell Home - gjm - last update 9/28/2000