RAID-10 on PE2850

Thu May 4 12:14:56 CDT 2006

FYI...that is not really RAID 10, it is actually a concatenated set of
mirrors. There is no striping at all.  

This was an interesting 'surprise' when going thru the docs online.  I don't
have the link handy, but with a bit of work you can find it, I think I ended
up having to get one of the Open Manage Array Manger docs for detailed info
on the PERC cards.  Seems Dell wants it to be VERY hard to find this
information.

James Howard
Storage Engineer
Rackspace Managed Hosting
jhoward at rackspace.com

-----Original Message-----
From: linux-poweredge-bounces at dell.com
[mailto:linux-poweredge-bounces at dell.com] On Behalf Of Lutz Birkhahn
Sent: Wednesday, May 03, 2006 11:06 PM
To: David Hubbard; linux-poweredge at dell.com
Subject: Re: RAID-10 on PE2850

David Hubbard wrote:
> Hit the space twice to select drives 0 and 1, hit enter to end (just 
> once), hit space twice to select drives 2 and 3, hit enter.  Then I 
> believe it's F10 to set up the logical drive

Hey, that was easy! Thanks a lot for saving my sanity! ;-)

> and you'll set it as raid one and it should indicate that it has two 
> stripes or something along those lines.

Yep, once I had used the "space space enter space space enter" cheat code
and pressed F10 ("Select Configurable Arrays"), I got two arrays offered. I
selected both arrays and pressed F10 again, and now the read-only field
showed "Span = YES". RAID-1 was the only option left, so I used that, and I
ended up with one single large logical drive, /dev/sda with the right size
(146G out of 4 x 73G drives).

Thanks again for saving the day,

/lutz

> > -----Original Message-----
> > From: linux-poweredge-bounces at dell.com 
> > [mailto:linux-poweredge-bounces at dell.com] On Behalf Of Lutz Birkhahn
> > Sent: Wednesday, May 03, 2006 11:19 PM
> > To: linux-poweredge at dell.com
> > Subject: RAID-10 on PE2850
> >
> > Before I start banging my head against the wall... Does anybody have 
> > a tip how to configure 4 drives on a PE2850 for RAID-10 or 1+0 or 
> > something like that?
> >
> > I spent the most part of today playing with the RAID BIOS program 
> > and reading tons of emails saying that others do it every day, but I 
> > still can't figure it out how to do it (I've configured many of 
> > these machines with RAID-1 or RAID-5 before, that works fine). From 
> > what I read on the list it seems you need to start with 2 RAID-1 
> > arrays and then somehow put them into the same Span (i.e. striping 
> > them)?
> >
> > I tried all kinds of variations, like selecting all 4 of the drives 
> > and build an array out of those (only offers RAID-0 or RAID-5)...
> >
> > Do you need a split backplane for RAID-10?? (we've ordered all of 
> > our machines with the 1x6 HD Backplane)
> >
> > These are the steps I've done so far:
> >
> > BIOS, hit ^M to enter RAID settings
> > - Configure -> New Configuration (all 4 drives show up on Channel 0)
> > - Select (with Space key) the first 2 drives (A00-00 and A00-01)
> > - hit Enter twice, shows the box "Select Configurable Arrays", only
> >   option I can select is A00: Span-1 (I tried not selecting it, but
> >   then I cannot continue; also didn't find any way to change this
> >   string).
> > - F10 (Configure), it shows:
> >
> >    LD  RAID   Size    #Stripes   StpSz   Drive-State
> >     0   1    69880MB      2      64KB    OPTIMAL
> >
> > - The RAID type field only offers RAID-0 or RAID-1 (no RAID-10 or so)
> >   so I keep it at RAID-1
> > - There is a line "Span = NO", but I cannot change it (when I hit 
> > Enter
> >   it says "Not An Option Item. Press Any Key To Continue")
> > - So I hit Enter on the "Accept" field and have 1 RAID-1 array:
> >
> >    RAID Ch-0                     RAID Ch-1
> >    ------------------------------------------------
> >    0: ONLIN A00-00
> >    1: ONLIN A00-01
> >    2: READY
> >    3: READY
> >
> > How do I proceed from here, or is this already wrong??
> >
> > I tried adding a 2nd RAID-1 array just like the first one, called 
> > A01, but at the "Select Configurable Array" it again only had one 
> > option,
> > "A01: Span-1", and I ended up seeing 2 disks in Linux (sda and sdb), 
> > which is not what I want...
> >
> > In case it matters, the System BIOS is A02, Version H430 (Feb 25, 
> > 2005), FW 521S.
> >
> > Chris Purcell wrote a while ago:
> > > from the Main Menu:
> > > Select Configure,
> > > Select View/Add,
> > > Arrow down to your drive(s),
> > > Select them using the spacebar,
> > > When drive selection is finished, press Enter, Now hit F-10, If 
> > > you aren't creating a Raid10, Raid50, etc, just a normal raid0, 
> > > raid1, or raid5, hit spacebar, then F-10 again,
> >
> > OK, but what *if* I do want to create a Raid10, Raid50, etc.??!
> >
> > TIA for any help or consolation...
> >
> > /lutz
> >
> > _______________________________________________
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> > Linux-PowerEdge at dell.com
> > http://lists.us.dell.com/mailman/listinfo/linux-poweredge
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