SCSI Mailbox Commands

SCSI Mailbox Commands

Post by Chris » Fri, 31 Mar 2006 03:06:31


Thanks Moojit. I found some more information. It's not a mailgram but a
mailbox. This is an EMC and in one document, I found the following:
"ELS buffers are needed to support Fibre Channel Extended Link
Services. ELS buffers are also used for SLI-2 FCP buffers (one per FCP
command) and Mailbox commands."

I am trying to understand where Mailbox commands fit in with SCN and
FCP commands. What are Mailbox commands used for?

Thanks!

ChrisW


http://www.yqcomputer.com/
 
 
 

SCSI Mailbox Commands

Post by scot » Fri, 31 Mar 2006 04:14:01

"ChrisW" < XXXX@XXXXX.COM > writes:

Communicating between the driver and the firmware on the HBA.

scott

 
 
 

SCSI Mailbox Commands

Post by Chris » Fri, 31 Mar 2006 07:44:36

> Communicating between the driver and the firmware on the HBA.

Thanks Scott. So this is for internal communication between the OS and
the physical card, kinda like a software interrupt?

The one thing that still does not make sense to me is how an HBA on a
server would send a mailbox command to an HBA on the storage device.

ChrisW
 
 
 

SCSI Mailbox Commands

Post by scot » Sun, 02 Apr 2006 04:15:38

"ChrisW" < XXXX@XXXXX.COM > writes:

It doesn't. It's likely that the error message you seen was the
result of an unsolicited event on the SAN fabric causing the target
device to recieve an odd mailbox message in the driver from its HBA.
Possibly an event initiated by a switch if you have a switched fabric
rather than arbitrated loop (AL).

The bulk of what goes on the fabric is encapsulated SCSI command data
blocks, plus the AL protocols (LIP etc.).

Hard to tell, really.

scott