On 2007-09-24, Nuno Fernandes <[EMAIL PROTECTED]> wrote:
>
> I disconnect the fibres that link FC Switch to DS4700 (to the active
> controller). It should send SCSI commands through passive links to ask the
> storage to failover the LUNs active controller. This isn't working.
What I think is happening here is that you might have:
'=' -- meaning active
'~' -- meaning passive
HBA1 ============ DS4x00 controller A ====== LUNx
HBA1 ============ DS4x00 controller B ====== LUNy
HBA2 ~~~~~~~~~~~~ DS4x00 controller B ~~~~~~ LUNx
HBA2 ~~~~~~~~~~~~ DS4x00 controller A ~~~~~~ LUNy
So when you fail active path for controller A, the rdac driver
wants to send a notification to controller B that it should
fail over, but ooops, the path for controller B is also gone.
What you seem to want is that it shouldn't fail over to
controller B, but rather use the standby path to controller A
(and B). And this is what I don't think is supported in the
RDAC driver, at least not the engenio/lsi version.
So, the correct configuration is:
HBA1 ============ DS4x00 controller A ===== LUNx
HBA1 DS4x00 controller A ~~~~~ LUNy
HBA2 ============ DS4x00 controller B ===== LUNy
HBA2 DS4x00 controller B ~~~~~ LUNx
And when you fail the path from HBA1 you'll get:
HBA1 x DS4x00 controller A ~~~~~ LUNx
HBA1 x DS4x00 controller A ~~~~~ LUNy
HBA2 ============ DS4x00 controller B ===== LUNy
HBA2 DS4x00 controller B ===== LUNx
And you'll get almost the same redundancy since you have
the active/passive paths between controllers and LUNs,
instead of between HBAs and controllers.
Am I making sense ? :-)
-jf
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