[dm-devel] [PATCH 0/2] 'default' hardware handler for multipath
Moger, Babu
Babu.Moger at netapp.com
Tue Apr 3 21:12:42 UTC 2012
Thanks Hannes. We appreciate your work on this.
> -----Original Message-----
> From: dm-devel-bounces at redhat.com [mailto:dm-devel-
> bounces at redhat.com] On Behalf Of Hannes Reinecke
> Sent: Monday, April 02, 2012 11:44 AM
> To: linux-scsi at vger.kernel.org
> Cc: dm-devel at redhat.com; Mike Snitzer
> Subject: [dm-devel] [PATCH 0/2] 'default' hardware handler for multipath
>
> This patchset introduces a 'default' hardware handler for dm-multipath.
> Modern storage arrays typically support two failover methods, the original
> proprietary and the modern ALUA-based one.
> The device_handler implementation will currently select the ALUA handler,
> and falling back to the proprietary one if ALUA isn't supported.
> However, in the built-in hardware table for multipath one can specify only
> one hardware handler, causing the original hardware handler to be
> overwritten.
> By specifying a 'default' hardware handler multipath will not try to attach a
> specific hardware handler, but rather using the currently attached on.
I think we still have some issues here. Right now we load the driver
either by adding it in initrd or by using request_module call from device mapper.
If the user passes, hardware_handler "1 default" from multipath then request_module will fail.
How are we going to load the driver if these handlers are not loaded.
>
> Hannes Reinecke (2):
> scsi_dh: Allow NULL hardware handler name in scsi_dh_attach()
> dm-mpath: Allow 'default' hardware handler
>
> drivers/md/dm-mpath.c | 8 ++++++--
> drivers/scsi/device_handler/scsi_dh.c | 8 ++++++--
> 2 files changed, 12 insertions(+), 4 deletions(-)
>
> --
> 1.7.7
>
> --
> dm-devel mailing list
> dm-devel at redhat.com
> https://www.redhat.com/mailman/listinfo/dm-devel
More information about the dm-devel
mailing list