[BC] RAID servers

[Bernie Courtney]

The problem, it seems, is that some people have had bad experiences with the
el-cheapo variety of RAID controllers and lumped them all together.

B

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Bernie Courtney
Metro Broadcast Services
bcourtney at metrobcast.com

On Fri, Mar 27, 2009 at 7:06 PM, <RichardBJohnson at comcast.net> pondered-

    There is a problem with some RAID controllers in that
    they require some software to be loaded into them (FPGA code)
    during the boot process. This usually happens when a driver
    is installed. The driver has a bucket full of bits that it
    uploads during its initialization. The problem exists that
    the RAID array is damn dumb until those bits are loaded.

    This means that the first disk in the array looks like something
    bootable to the BIOS, but none of the other drives are even
    known to exist. If the RAID array is supposed to support
    booting, then it needs to be built (using software) so
    that it can handle the boot process.

    Under Linux, any such RAID array is initialized so that the
    first disk in the array contains the boot partition plus any
    striping for the rest of the array. This is fine unless you
    lose that first disk. If it’s lost, you can’t boot normally.

    However, Linux has a work-around where you boot the installation
    DVD. This loads the drivers. Then, you can execute a shell and
    rebuild the array as well as repartition a new boot disk after
    which you reinstall the boot loader (grub).

    Better RAID devices load their own FPGA code when they are reset.
    The FPGA code is in a serial EEPROM that costs about a dollar.
    Other companies that make RAID controllers are so cost conscious
    (read cheap) that they cause all kinds of problems to save that dollar.

    Cheers,
    Richard B. Johnson
    Book: http://www.AbominableFirebug.com/