[CentOS] looking for RAID 1+0 setup instructions?

[Christopher Chan]

>> You know what, let me try just that today, I have a new install to do, so
>> I'll try pre-creating a RAID10 on install and report back. First I'll try
>> layered MD devices and then I'll try creating a RAID10 md device and we'll
>> see if it can even boot off them.
>>     
>
> Ok, I verified that inside anaconda one cannot create layered MD RAID
> arrays because once one forms an array there is no choice to create a
> volume of type "Software RAID". The RAID choices are RAID0, RAID1,
> RAID5 or RAID6 during install, no RAID10.
>   
> I can create multiple RAID1s though, of type "LVM Physical Volume" and
> then create a volume group composed of those. I can then create a root
> LV and a swap LV, though these will not be striped because LVM doesn't
> default to striping PVs, but concatenating, so in order to stripe
> these I'll need to leave enough free space to create striped versions,
> dump and restore from the old root to the new root and then edit the
> fstab/grub, run mkinitrd and reboot. Not exactly convenient, but
> unfortunate due to LVM's default policy of concatenating PVs instead
> of striping them... oh well.
>   
> As far as creating a RAID10 at the command prompt, the dm-raid10
> kernel module is missing from the install image, so no luck directly
> creating a RAID10, and after a couple of reboots I was able to create
> a layered setup, but anaconda didn't recognize it (either immediately,
> or after a reboot) to be able to perform an install on it because it
> doesn't start the arrays upon startup to be able to find the nested
> one.
>   
No surprise about raid10. I take it you tried this with Centos 5? Thanks 
for the testing. I cannot believe that it is no longer possible in 
Centos4/RHEL4 and later. I had done it too with Fedora Core 2 which is 
2.6.4 based.

> So if it worked for you in RH9, it no longer works anymore.
>
> Maybe because RH9 had a separate MD RAID implementation and not the
> device-mapper implementation.
>   

RH9 was 2.4 and had no fancy dm. BTW, md raid is still separate. But you 
have already said in your other post.