how to setup linux software raid 10

[Denis Melnikov]

> I managed to get RAID working partially. It took me a while 
> to figure out how to do it.
> RAID doesn't come up as an option on the initial screen, so I 
> thought I would document what I did for others who wonder how 
> to access the RAID function from the installer. 
> 
> 1. I got to the partition stage of the installation (on the 
> standard install).
> 2. For each of my 4 disks I created a partition.
> 3. I selected each parttion one by one and set it as physical 
> partition for RAID. 
> Once the disks are assigned as RAID, the setup RAID option 
> appears on the main screen.
> 4. Select Setup RAID,
> 5. Assign RAID 1 to the first two drives, with on spare.
> 6. Do the same for the next pair of drives. 
> At this point it is possible to set up LVM. But I want to do 
> RAID 0 on the 2 RAID 1 devices.
> It doesn't seem possible to do this from the installation 
> partition manager.
> 
> How can I take my pairs of RAID1s and make them into RAID10? 
> Can I continue the installation setting up LVM one of the 
> RAID1s then once the system is setup run mdadm to make a 
> raid0 out of the two raid pairs?

Yes. You can make up a volume of several partitions including
RAID ones.

Make sure you have /boot on a separate RAID1 partition,
because GRUB cannot load from LVM prepared one.

> Or is there a better way?

Can you make a RAID partition for RAID0 over previously
prepared RAID1 partition? Unfortunately, I cannot try it now.

Denis


> I was thinking of setting up one 320GB RAID10 drive with one 
> LV and using the guided partitioning within the LV. Would 
> that be a reasonable approach? 
> 
> Thanks,
> Krsnendu dasa
> 
> 
> On 26/08/07, Scott Balneaves <sbalneav at legalaid.mb.ca> wrote: 
> On Sat, Aug 25, 2007 at 12:35:38PM -0700, Joe Rowe wrote:
> >
> > Like myself,
> > More and more people are using Edubuntu or Ubuntu 
> > servers or critical workstations with inadequate plans for 
> Disk failure.
> >
> >
> > Anyone,
> > Please reply if you have done software RAID on Ubuntu/Edubuntu
> > and you are good at documenting steps by step tips. 
> 
> I've done software raid for years and years.  It's pretty 
> easy, and just
> required doing a bit of reading and understanding.  The 
> O'Reilly "Managing Raid
> on Linux" is an excellent book on the subject. 
> 
> Scott
> 
> --
> Scott L. Balneaves | "Eternity is a very long time,
> Systems Department |  especially towards the end."
> Legal Aid Manitoba |    -- Woody Allen