SUMMARY: JBOD / passthrough mode on LSI MegaRAID SAS 9261-8 aka Sun Storage 6 Gb/s SAS PCIe RAID HBA SG-SAS6-R-INT-z ?

From: Anthony D'Atri <>
Date: Mon May 23 2011 - 05:43:11 EDT
Preface:  why on earth does Sun / Oracle default to goofy RAID HBA's when ZFS
and even SVM provide superior mirroring?  AFAICT there isn't a functional way
to interrogate the status of RAID volumes on this HBA from the OS -- how is
one supposed to monitor for disk failures?

I ended up managing to delete whatever volume came from the factory via the
misnamed WebBIOS.  Fired up the Java remote console and fished around via
<tab> and Enter until I found an option to do so.  The installation guide for
this card only touches on the bizarre pre-boot CLI, but a statement that the
syntax is the same as the MegaCLI utility led me to a user's guide for the
latter, from which I synthesized that

-cfgldadd -r0[252:0] -a0
-cfgldadd -r0[252:1] -a0
-cfgldadd -r0[252:2] -a0
-cfgldadd -r0[252:3] -a0

performs the workaround of creating four degenerate whole-disk stripes that
can be seen by BIOS and the OS, and thence ZFS'd.  There is of course the
usual uncertainty about booting off the mirror if the primary fails, thanks to
the miserable legacy of BIOS.

A bit of clarification of the above syntax:  on SPARC hosts, commands are
prefixed with "cli", and one selects an HBA from potentially several ahead of
time, much like one does with ndd on certain older ethernet interfaces. On x86
hosts every command has to specify the desired HBA.  I guessed that the first
would be 0, and that worked.  The 252 seems to be the SES enclosure ID for
internal disks; 0-4 should be obvious.

The moral of the story is to be very, very sure that new systems you order
come with normal, non-RAID HBA's.

> I've searched the web and found only others asking this, with a few hints
but no answers.
> I have an x4170m2 that was purchased by someone outside the company that
came with one of these pointless RAID HBA's.  I'm trying to figure out how to
get the thing to simply present the four disks attached to it to BIOS and the
OS as-is, without RAID games, so that I can set up customary ZFS goodness on
> I entered a ticket with Soracle, and so far the tech's response has been
that he's never heard of this card -- despite the fact that it's what the
system ships with by default!
> The BIOS configuration utility presented by the card is even worse than the
typical PC-oriented card:  the textual interface is a CLI that's cryptic
beyond belief, and "WebBIOS" turns out to only work on a graphical console,
with the usual limited compatibility with ILOM's remote console utility (eg.
the mouse doesn't work).  I managed to destroy whatever volume it had
configured from the factory, but can't figure out how to get it to pass
through the disks, or even set up stupid one-disk virtual volumes.
> I tried booting diskless and using megacli, but when I grab that from
Intel's web site and run it, it doesn't appear to even see the HBA.  The HBA
at power-on does report four attached disks.
> So, I'm hoping that someone out there might have an idea of how to bypass
the onboard RAID lunacy on this card so that I can get the system installed
and in production.  I'll summarize as appropriate.  Thanks!
sunmanagers mailing list
Received on Mon May 23 05:43:47 2011

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