RHEL5, MegaRAID driver and emulation modes

[Derek Yuen]

Hi,

Being a little eager to try out RHEL5, I thought I should read the release
notes before I install.

The release mentions the following about the MegaRAID HBA and the
emulation modes it should run in, specifically, in the "Known Issues"
section:

----
From,
https://www.redhat.com/docs/manuals/enterprise/RHEL-5-manual/release-notes/RELEASE-NOTES-x86-en.html

Known Issues

    * Host bus adapters that use the MegaRAID driver must be set to
      operate in "Mass Storage" emulation mode, not in "I2O" emulation
      mode. To do this, perform the following steps:
         1.  Enter the MegaRAID BIOS Set Up Utility.
         2.  Enter the Adapter settings menu.
         3.  Under Other Adapter Options, select Emulation and set it to Mass Storage.

If the adapter is incorrectly set to "I2O" emulation, the system
will attempt to load the i2o driver. This will fail, and prevent the
proper driver from being loaded.

Previous Red Hat Enterprise Linux releases generally do not attempt
to load the I2O driver before the MegaRAID driver. Regardless of this, the
hardware should always be set to "Mass Storage" emulation mode when used
with Linux.

----

A previous thread on a mailing list talked about I2O vs. Mass Storage
modes on the Dell PERC Controller,

http://lists.freebsd.org/pipermail/freebsd-questions/2006-May/121509.html

A little dated but the concepts still apply.

Is this of any concern ?  Can anyone comment on this topic ?



Thanks,
/dky