[dm-devel] Re: [ANNOUNCE] multipath-tools-0.3.4

[Douglas Gilbert]

christophe.varoqui at free.fr wrote:
> Selon Arjan van de Ven <arjan at infradead.org>:
> 
> 
>>On Mon, 2004-10-25 at 00:14 +0200, christophe varoqui wrote:
>>
>>
>>>	* multipath & multipathd now use the same path checkers.
>>>	  Consequence being multipath now need sg loaded
>>
>>why sg and not using SG_IO on the actual devices ?
>>mp-tools are 2.6 only anyway, right ?
>>
> 
> Glad you notice :)
> 
> In fact all the sg stuff I use is done with the SG_IO ioctl (see
> libcheckers/*.c)
> But somehow, it doesn't work as expected. I don't remember how exactly it failed
> in my tests but it did ... I remembered receiving bad path status and
> experiencing blocked checkers.
> 
> I would really like someone experienced put his nose in this stuff. If you want,
> I can code up a flag to switch the mp-tools ioctl submission between blockdev
> and sgdev.
> 
> Note you don't need to have real multipathed hardware to run and test the thing
> : parallel SCSI hw suffice and is seen as monopath.

A significant patch from Patrick Mansfield concerning the
error reporting of the block layer SG_IO ioctl is present
in lk 2.6.10-rc1 . It was not present in lk 2.6.9 and earlier.

Doug Gilbert