Diskconfig with RAID and LVM

[Michael Tautschnig]

> Hi all,
> 
> I am a newbie in unix cluster as well as debian. My lab has a cluster.
> The main server has RAID. There are 8 disks. The control card has a
> bios. When it boots, I have an option to build a raid array (volume,
> RAID0 (stripe), RAID5 or RAID10(stripes of mirror)). However, some of
> these options (RAID5 and RAID10) were not regconized by Debian sarge
> kernel (I think the kernel version is 2.6.9-k8). I got an image CD
> build on Feb, 2005 for AMD64. Furthermore, Debian sees it as a single
> SCSI. If at boot I build more than a single array, Debian would see
> defferently. Since I am a newbie, I would like to have your opinions.
> Should I do one of the following and which one is the best option?
> 
The idea of hardware RAID - that is the one that is configured using the BIOS -
that the operating system does not see anything but a single disk, everything
else is managed by the hardware itself!

> 1) Install Debian and let Debian kernel control the raid on all 8 disks.
> 2) At boot, using software make 4 arrays, then install debian and let
> debian make an raid arrays from 4 scsi "disks"
> 
If you got such a great controller, you should prefer the hardware-only
solution. Actually I haven't got any idea why one would use software RAID in
such a case.

> If you have better idea, I would really appreciate your telling me. A
> concrete example would be great.
>

Well, the question is - what is most important? Speed or security? How much
diskspace is required? Using RAID 5 could provide the space of 7 disks, RAID10
would only provide the space of 4 disks.

Regards,
Michael