RAID with ICH8 fakeRAID, dm_mod module loaded, /dev/mapper empty?

dezza · 2008-10-23 05:02:12

Hello everyone.

I've wanted for a long time to get my hands diry with RAID on Linux.. I haven't tried it on Windows previously, so that might explain if I've forgotten something ..

I've set my options in the BIOS to "RAID" instead of "AHCI" and I've created an RAID1-mirror array (2x500GB) in the RAID-BIOS accessed by CTRL-I on bootup.

I have an ICH8 chipset and I was told/read somewhere to use dmraid, so I modprobed dm_mod, raid1, and ran "dmraid -ay", (Is this all that is needed?)

But nothing is listed in /dev/mapper/, only a file called control, but if I list RAID sets with "dmraid -s" it shows up fine as a RAID1-mirror array like so:

# dmraid -s

*** Group superset isw_fccfdfjb
--> Subset
name   : isw_fccfdfjb_store
size   : 976764928
stride : 128
type   : mirror
status : ok
subsets: 0
devs   : 2
spares : 0

# dmraid -r

/dev/sdc: isw, "isw_fccfdfjb", GROUP, ok, 976771053 sectors, data@ 0
/dev/sdb: isw, "isw_fccfdfjb", GROUP, ok, 976773166 sectors, data@ 0

Thanks in advance!

EDIT: I found this in dmesg, does this mean there's a problem with dmraid communicating with the RAID bios or?

device-mapper: uevent: version 1.0.3
device-mapper: ioctl: 4.13.0-ioctl (2007-10-18) initialised: dm-devel@redhat.com
device-mapper: table: 254:0: mirror: Device lookup failure
device-mapper: ioctl: error adding target to table
device-mapper: table: 254:0: mirror: Device lookup failure
device-mapper: ioctl: error adding target to table
device-mapper: table: 254:0: mirror: Device lookup failure
device-mapper: ioctl: error adding target to table
device-mapper: table: 254:0: mirror: Device lookup failure
device-mapper: ioctl: error adding target to table
device-mapper: table: 254:0: mirror: Device lookup failure
device-mapper: ioctl: error adding target to table
md: raid1 personality registered for level 1
device-mapper: table: 254:0: mirror: Device lookup failure
device-mapper: ioctl: error adding target to table

Last edited by dezza (2008-10-23 05:05:32)

byte · 2008-10-23 06:31:19

Don't load raid1. That's for md, which is classic software (non-bios) RAID.

dezza · 2008-10-23 06:51:42

byte wrote:

Don't load raid1. That's for md, which is classic software (non-bios) RAID.

Okay, but is there anything else missing or is it just because it's a weird piece of hardware?

http://www.gigabyte.com.tw/Support/Moth … uctID=2453

This is my motherboard. GA-965P-DQ6 with Intel P965+ ICH8R chipset

Let me get this right, the thing that should happen when I type "dmraid -ay" is that I should be able to see and mount my "raid-array" in /dev/mapper/isw_fjefdkfj_store (something like this) like a normal disk from /dev/sd* or /dev/hd* right? Cause I have just got into RAID and all the different kinds when I wanted to create this array.

byte · 2008-10-23 07:06:11

Yep, that's what should happen. I have such a setup myself: ICH10R, 2x500GB RAID1, LVM on dm-crypt on dmraid.

dezza · 2008-10-23 07:16:37

Weird.. Are there any BIOS configurations which collide with dmraid or somehow makes it difficult to make it spin right?

What is the most practical approach to making a 2x500GB RAID1 (Mirror) array in Linux? I know you can do all kinds of other fancy things and that RAID1 is far from one of the most advanced RAID-setups, but I really feel like there are far too many ways to combine LVM and RAID, and it looks like both RAID and LVM can do some of the same things, so what is smartest?

Mikko777 · 2008-10-23 09:52:57

dezza wrote:

Weird.. Are there any BIOS configurations which collide with dmraid or somehow makes it difficult to make it spin right?
What is the most practical approach to making a 2x500GB RAID1 (Mirror) array in Linux? I know you can do all kinds of other fancy things and that RAID1 is far from one of the most advanced RAID-setups, but I really feel like there are far too many ways to combine LVM and RAID, and it looks like both RAID and LVM can do some of the same things, so what is smartest?

http://wiki.archlinux.org/index.php/Ins … AID_or_LVM

I used that. Software raid > "bios" raid.

dev/mapper is for lvm afaik. /dev/md for raid.

Oh and you might want to practice in Virtualbox before you install.

Heres how i partitioned:

sda 500Gb: sdb 500Gb:
md1= sda1 boot 150Mb ext2 raid1 sdb1 boot 150Mb ext2 raid1
sda2 Vista 30Gb NTFS sdb2 VistaData 30Gb NTFS
md0= sda3 LVM 470Gb ext3 raid0 sdb3 LVM 470Gb ext3 raid0

md1=sda1=/boot=ext2
md0=LVM:
/dev/array/root 25GB inherit ext3
/dev/array/swap 5GB contiguous swap
/dev/array/home 846.37GB inherit ext3

-ext3 will be converted to ext4 later

Last edited by Mikko777 (2008-10-23 09:53:51)

dezza · 2008-10-27 16:21:52

I do not want to install on RAID, I already have a 10k RPM raptor disk where my system resides, I only want to create a 2x500GB RAID1 disk to store random important files on.

Last edited by dezza (2008-10-27 16:22:03)

dezza · 2008-10-28 01:15:33

I found this excellent howto since the damn fakeRAID thing keeps getting no device.
http://www.howtoforge.com/redundant-arr … ical-paper

Last edited by dezza (2008-10-28 01:16:02)

Arch Linux

#1 2008-10-23 05:02:12

RAID with ICH8 fakeRAID, dm_mod module loaded, /dev/mapper empty?

#2 2008-10-23 06:31:19

Re: RAID with ICH8 fakeRAID, dm_mod module loaded, /dev/mapper empty?

#3 2008-10-23 06:51:42

Re: RAID with ICH8 fakeRAID, dm_mod module loaded, /dev/mapper empty?

#4 2008-10-23 07:06:11

Re: RAID with ICH8 fakeRAID, dm_mod module loaded, /dev/mapper empty?

#5 2008-10-23 07:16:37

Re: RAID with ICH8 fakeRAID, dm_mod module loaded, /dev/mapper empty?

#6 2008-10-23 09:52:57

Re: RAID with ICH8 fakeRAID, dm_mod module loaded, /dev/mapper empty?

#7 2008-10-27 16:21:52

Re: RAID with ICH8 fakeRAID, dm_mod module loaded, /dev/mapper empty?

#8 2008-10-28 01:15:33

Re: RAID with ICH8 fakeRAID, dm_mod module loaded, /dev/mapper empty?

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