Re: install Etch with raid level 10

[Scott Lair <scott@lairhome.com>]

Dave Ewart wrote:

> On Wednesday, 26.09.2007 at 09:49 -0400, Scott Lair wrote:
> 
> > I tried to install Etch on AMD64 using raid level 10.  After I
> > partitioned the drives, I went to create the md devices and could only
> > choose from raid levels 0,1 or 5.  Should I be able to install with
> > level 10?  I tried the latest netinst.iso and the cdrom install disk 1
> > with the same results.
> 
> There is no direct support for RAID-10 via software RAID, you have to
> make yourself two RAID-1 arrays and then apply a second layer of
> software RAID-0 over the top.
> 
> The installer may not support RAID-10 directly because of the
> multi-layer approach.
> 
> Normally, one makes a RAID-10 software setup as follows:
> 
> mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sd[ab]1
> mdadm --create /dev/md1 --level=1 --raid-devices=2 /dev/sd[cd]1
> mdadm --create /dev/md2 --level=0 --raid-devices=2 /dev/md[01]
> 
> I'd be interested to know if you can approach the installation in the
> same way, actually.

I'll try setting up the disks as you suggest, then run the install.
I did manage to get the raid10 module loaded during the install,
but the option for RAID-10 would not show up in the installer.
I'll try creating the RAID-10 array after loading the module also.
I'm getting the feeling here already that this is probably 
something I ought not to mess with. This is going to be a 
production machine, so I may end up with a RAID-1 for /boot
and /, then run RAID-10 for shared data. I suppose that
would be a reasonable solution.

I've got some time to mess with it for a while and I'll post
back the results.

thanks,

scott