# Could not mount specified ROOT, try again

## Leachim

Hello, I have Gentoo 2007.0 on this PC:

MB: Asrock 4core1333-Viiv

CPU: Intel Core 2 Duo E4400

RAM: 4gb DDR2

HDD: 2x WD Raptor 36G 10k rpm

2x Hitachi 160GB

And Im using RAID1 array.... I have that two WD's in one RAID1 array and other two Hitachi disks in other RAID1 array. It's Hardware array, not software..

I have followed te steps in this article> http://gentoo-wiki.com/HOWTO_Gentoo_Install_on_Bios_(Onboard)_RAID.

When I have rebooted my pc, I get this message:

```
>> Activating mdev

>>Activating Device-Mapper RAID(s)

ls:  : No such file or directory

>> Determining root device...

>> Mounting root...

mount: Mounting /dev/mapper/isw_cfecbgiggj_System on /newroot failed: Invalid argument

!! Could not mount specific ROOT, try again

!! Could not find the root block device in .

Please specity another value or: press Enter for the same, type "shell" for a shell, or "q" to skip

root block device()  : :
```

```
(chroot) livecd / # ls /dev/mapper

control  isw_cfecbgiggj_System  isw_cfecbgiggj_System1  isw_cfecbgiggj_System2  isw_cfecbgiggj_System3  isw_dbiagcaedf_Data

(chroot) livecd / #
```

Fstab:

```
/dev/mapper/isw_cfecbgiggj_System1              /boot           ext2            noauto,noatime  1 2

/dev/mapper/isw_cfecbgiggj_System3              /               ext3            noatime         0 1

/dev/mapper/isw_cfecbgiggj_System2              none            swap            sw              0 0

/dev/mapper/isw_dbiagcaedf_Data                 /data           ext3            noatime         0 1

/dev/cdrom              /mnt/cdrom      audo            noauto,ro       0 0

shm                     /dev/shm        tmpfs           nodev,nosuid,noexec     0 0

none        /proc        proc    defaults             0 0

none        /dev/shm     tmpfs   nodev,nosuid,noexec  0 0
```

----------

## albatroz

Hi,

I had today for the first time the same problem. I don't know much about raids, but to solve my problem I had first load to the module for the disk:

```

modprobe sd_mod

```

Now I need to know how to do it automatically.

hope it helps.

----------

## NeddySeagoon

albatroz,

You must build SCSI Disk support into your kernel, not as a module.

BIOS Fakeraid should not be used on Linux only systems. The only reason for using it is that the raid set must be shared with Windows.

Kernel raid gives much less trouble, is better tested and supported and the resulting raid sets are not tied to a particular BIOS.

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## Leachim

And software raid does not slowing the system?

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## NeddySeagoon

Leachim,

You have software raid now - provided by your BIOS.

Raid1 and Raid0 have very low system impacts as there is no redundant data to calculate.

Raid0 rearranges the data on the drives, its faster but not fault tolerant.

Raid1 makes a copy of the data. Writes have to be done twice.

This is regardless of the software implementaion (be it kernel or BIOS)

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## Leachim

So it is better use kernel RAID1 than FAKE RAID1?

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## NeddySeagoon

Leachim,

Yes. With kernel raid you can move the raid set around (physically) no need for the same hardware.

If your motherboard breaks, you have a backup don't you ?

BIOS Raid is tied to the BIOS. It may not work with another motherboard.

You may mix raid levels with kernel raid too as you donate partitions to raid sets.

e.g. on one pair of drives I have 

```
Personalities : [raid0] [raid1] 

md1 : active raid0 sdb5[1] sda5[0]

      9783296 blocks 16k chunks

      

md2 : active raid0 sdb6[1] sda6[0]

      58604928 blocks 16k chunks

      

md3 : active raid0 sdb7[1] sda7[0]

      3919616 blocks 16k chunks

      

md4 : active raid0 sdb8[1] sda8[0]

      11727232 blocks 16k chunks

      

md5 : active raid0 sdb9[1] sda9[0]

      31262208 blocks 16k chunks

      

md6 : active raid0 sdb10[1] sda10[0]

      468712192 blocks 16k chunks

      

md0 : active raid1 sdb1[1] sda1[0]

      40064 blocks [2/2] [UU]

      

unused devices: <none>
```

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## Leachim

Now I have next problem -> https://forums.gentoo.org/viewtopic-t-688031-highlight-.html  :Crying or Very sad: 

----------

