I've gotten some time recently to spend on working on my home linux box. It rarely happens and is usually some very new concepts for me. One of the things that's been plagueing me recently is safe storage. I mean I have 11,000 mp3's it's about 77 gigs of data. Where does one put all that, and how does one keep it safe?

By using reduntant array of inexpensive disks (RAID). There are 6 different levels of raid. I'm only interested in RAID1 which is mirroring. That means that each disk has an identically sized disk whose data is kept in sync. So there are redundant copies of all your data.

I've spent a good amount of time crafting a linux filesystem. It's debian woody tailored to a linux-from-scratch style but with the tangential focus of a child-of-slackware. It's a good system, but it took a while to setup. It took me a long time (days) to setup and losing it would cost me more days.

So, I'm running from SCSI raid. I ordered two IBM 10,000rpm scsi drives from some pakistanny hardware shop. I decided to use LVD/SCSI3 for speed and reliability. Supposedly scsi disks are made to a higher snuff, and the bus is more tolerant and verbose about hardware failures. So, they are acting as my root partition. Both disks have the linux kernel on their MBR to facilitate easy reboot on disk failure. See my lilo.conf later.

Next is storage. Like I said. I have 77 gigs of MP3's and local household data. I also had about 70 more gigs of other people's mp3s sitting on smaller ide harddisks. The best hard drives you can get reasonably now are about 120gigs. That is to small. So I'm going to combine some disks.

A side note IDE DMA with linux and the supermicro 370de6 seems to be broken. I was getting horrible read errors and geometry miscalculations when I attached devices to my second IDE chain. I farked up bad when I changed the geometry on my drive because of the reports from the second IDE controller that I misinterpreted. I lost all my household data. Thankfully most of the tunage has been duped by other people and is on me and Olivia's laptops. Otherwise I'd be crying at the loss of many hours of work.

But after surmounting all the idiosyncracies of ide/scsi on my mother board, booting off raid, and LVM. I've got a system all worked out.

I'm using two samsung 120gig drives as one raid1 storage array. Then I have some old maxtor 100gig drives that I'm using as a second raid1 array. Then I used the 2.4 kernel's built in logical volume management support to combine the two raid1 volumes into one logical volume. That's a total of 220gigs of raid1 space!

To maximize performance, I've put a drive from each raid1 array on an IDE controller. See the diagram. I'll include some of my files below for safe keeping and reference.

/etc/lilo.conf for booting from raid1

lba32
boot = /dev/md0
append="md=0,/dev/sda1,/dev/sdb1"
raid-extra-boot="/dev/sda,/dev/sdb"

disk=/dev/sda bios=0x80
disk=/dev/sdb bios=0x80

image = /2.4.19-raid
  label = linux
  root = /dev/md0

/etc/raidtab sets up the three raid1 disks

# root filesystem
# 9 gig ibm's
raiddev /dev/md0
        raid-level 1
        chunk-size 8
        nr-raid-disks 2
        nr-spare-disks 0
        persistent-superblock 1
        device  /dev/sda1
        raid-disk 0
        device /dev/sdb1
        raid-disk 1

# first raid1 pair
# 120 gig samsungs
raiddev /dev/md1
        raid-level 1
        chunk-size 8
        nr-raid-disks 1
        nr-spare-disks 0
        persistent-superblock 1
        device  /dev/hda1
        raid-disk 0
        device /dev/hdc1
        raid-disk 1

# second raid1 pair
# 100gig maxtors
raiddev /dev/md2
        raid-level 1
        chunk-size 8
        nr-raid-disks 2
        nr-spare-disks 0
        persistent-superblock 1
        device  /dev/hdb1
        raid-disk 0
        device /dev/hdd1
        raid-disk 1

/etc/fstab shows my VG & LV names

# /etc/fstab: static file system information.
#
# <file system> <mount point>   <type>  <options>               <dump>  <pass>
/dev/md0  /       reiserfs      defaults        0       1
#/dev/vg0/lv0       /mnt/family      reiserfs        defaults        0       0
proc      /proc   proc  defaults                0       0
/dev/fd0  /floppy    auto       user,noauto             0       0
/dev/cdrom      /cdrom          iso9660 ro,user,noauto          0 0
/tmp/swap  swap  swap  defaults  0  0

Anyway. That's how I'm doing it. The samsung disks are only $120 dollars. SO for $480 you could have 240 gigs of reduntant IDE storage. I know that scsi is better, but I don't have the $2k that it would take to build comparable space in scsi.