HPDL320 raid issue

[-Alexg-]

Greetings,

I have a issue with a HPDL320 G5 server.

Initially, it had a RAID 1 with two disks. After installing CentOS, fdisk show this output:

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# fdisk -l

Disco /dev/sda: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders
Unidades = cilindros de 16065 * 512 = 8225280 bytes

Disposit. Inicio Comienzo Fin Bloques Id Sistema
/dev/sda1 * 1 13 104391 83 Linux
/dev/sda2 14 19116 153444847+ 83 Linux
/dev/sda3 19117 19371 2048287+ 82 Linux swap / Solaris
/dev/sda4 19372 19435 514080 5 Extendida
/dev/sda5 19372 19435 514048+ 83 Linux

Disco /dev/sdb: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders
Unidades = cilindros de 16065 * 512 = 8225280 bytes

Disposit. Inicio Comienzo Fin Bloques Id Sistema
/dev/sdb1 * 1 13 104391 83 Linux
/dev/sdb2 14 19116 153444847+ 83 Linux
/dev/sdb3 19117 19371 2048287+ 82 Linux swap / Solaris
/dev/sdb4 19372 19435 514080 5 Extendida
/dev/sdb5 19372 19435 514048+ 83 Linux

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It shows two separate disks instead the BIOS RAID 1 configuration, but both disks seems to have the same data.

Now, I installed two additional disks, created another RAID 1 in the bios, and fdisk show two more separated disks:

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# fdisk -l

Disco /dev/sda: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders
Unidades = cilindros de 16065 * 512 = 8225280 bytes

Disposit. Inicio Comienzo Fin Bloques Id Sistema
/dev/sda1 * 1 13 104391 83 Linux
/dev/sda2 14 19116 153444847+ 83 Linux
/dev/sda3 19117 19371 2048287+ 82 Linux swap / Solaris
/dev/sda4 19372 19435 514080 5 Extendida
/dev/sda5 19372 19435 514048+ 83 Linux

Disco /dev/sdb: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders
Unidades = cilindros de 16065 * 512 = 8225280 bytes

Disposit. Inicio Comienzo Fin Bloques Id Sistema
/dev/sdb1 * 1 13 104391 83 Linux
/dev/sdb2 14 19116 153444847+ 83 Linux
/dev/sdb3 19117 19371 2048287+ 82 Linux swap / Solaris
/dev/sdb4 19372 19435 514080 5 Extendida
/dev/sdb5 19372 19435 514048+ 83 Linux

Disco /dev/sdc: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders
Unidades = cilindros de 16065 * 512 = 8225280 bytes

Disposit. Inicio Comienzo Fin Bloques Id Sistema
/dev/sdc1 1 19457 156288321 83 Linux

Disco /dev/sdd: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders
Unidades = cilindros de 16065 * 512 = 8225280 bytes

El disco /dev/sdd no contiene una tabla de particiones válida

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It seems that BIOS raid is not working with those two new disks but pressing F8 show both raids OK. Then I only can format both separately...

Any advice?

Regards

[wobbe]

Looks to me that you are using a fakeraid controller without the proper linux driver installed. Sata raid controller perhaps?

Anyway, after setting up the raid in the bios you need to use a driver disk during install time. You should see only one disk when executing fdisk -l
If you have a sata raid controller you are not running raid at this moment!

[-Alexg-]

Thanks for the response wobbe!

Yes, it's a sata raid controller (DL320 G5). This is a production server so I think it will be better to keep it without modifying raid now...

The strangest thing to me is that fdisk -l shows two identical disks, with the same data! as you said, like a fake raid 1...

Hope not to have a disk failure, this raid configuration looks bad...

Best regards.

[TTr]

The embedded raid controller on this server is a BIOS based raid controller. That means that the raid is software based and it is in the BIOS. Windows OSes amke BIOS calls for their storage needs and will see the two disks as one raid-ed volume.

However Linux does *not* make BIOS calls for the storage and instead talks directly to the hardware. Therefore it does not see the raid volume, it sees two identical disks. The two disks will not fail over if there is a disk failure amd more importantly will go out of sync very quickly since Linux will only be writing to one disk.

> Hope not to have a disk failure, this raid configuration looks bad...

There is no raid configuration in this case. You should look into creating a Linux based software raid of the two disks.

[wobbe]

I think the best thing to do, if you want to continue using this o.s. installation, is to remove one of the disks and disable the raid controller.