An array failover driver

An array failover driver

[Qi, Yanling]

Hi All, 

I am going to develop a multiple-pathing driver to support our storage array
hardware on Linux(2.4 and later). I prefer the driver sit on the top of HBA
drivers (fibre channel adapter drivers) and below middle level (the unifying
layer). In other words, insert my pseudo driver into middle level and lower
level drivers. The driver will take care of path failover. I am still in
research phase. Do you have any suggestions?

  
Thanks, 
  
Yanling Qi 

Re: An array failover driver

[Steven Dake]

There is a failover driver as part of the MD driver system.  I think 
someone has worked on a SCSI multipathing driver that automatically 
picks up redundant paths and fails over on retries, etc.

-steve

Qi, Yanling wrote:

>Hi All, 
>
>I am going to develop a multiple-pathing driver to support our storage array
>hardware on Linux(2.4 and later). I prefer the driver sit on the top of HBA
>drivers (fibre channel adapter drivers) and below middle level (the unifying
>layer). In other words, insert my pseudo driver into middle level and lower
>level drivers. The driver will take care of path failover. I am still in
>research phase. Do you have any suggestions?
>
>  
>Thanks, 
>  
>Yanling Qi 
>-
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>
>
>  
>

Re: An array failover driver

[Steve Ralston]

On 12/19/2002 03:56 PM, Qi, Yanling wrote:

>Hi All, 
>
>I am going to develop a multiple-pathing driver to support our storage array
>hardware on Linux(2.4 and later). I prefer the driver sit on the top of HBA
>drivers (fibre channel adapter drivers) and below middle level (the unifying
>layer). In other words, insert my pseudo driver into middle level and lower
>level drivers. The driver will take care of path failover. I am still in
>research phase. Do you have any suggestions?
>  
>

I've been there & done that, for drivers/message/fusion drivers (aka for 
FC9x9 HABs).
The dynamic multi-pathing failover driver I wrote acted as sort of a shim,
sitting logically between the scsi midlayer and {mptbase+mptscsih} 
driver(s),
sort of exactly as you describe above.  The source is available via:
  ftp://ftp.lsil.com/pub/symchips/fibre_ch/Metastor/dmpath-2.01x25.tar.gz

Which HBA driver are you looking at doing this for?