Re: RE: Temporarily squelching multipathd errors

[Konrad Rzeszutek <konrad@virtualiron.com>]

On Fri, Nov 21, 2008 at 01:54:01PM -0600, Daniel Keisling wrote:
> I am still getting multipath errors when unpresenting and presenting
> LUNs.  I've traced it down to getting path failures everytime I either
> remove or add a LUN to the system.  The strange thing is that I get path
> errors for maps that aren't related to the LUNs I am deleting or adding.
> In this case, I am deleting the LUN with the map 'mpath18,' but other
> maps complain whenever the LUN is deleted:
> 
> Nov 21 13:47:05 ausracdbd01 multipathd: checker failed path 67:208 in
> map orabackup_hs
> Nov 21 13:47:05 ausracdbd01 kernel: device-mapper: multipath: Failing
> path 67:208.
> Nov 21 13:47:08 ausracdbd01 multipathd: checker failed path 70:160 in
> map mpath18
> Nov 21 13:47:08 ausracdbd01 kernel: device-mapper: multipath: Failing
> path 70:160.
> Nov 21 13:47:09 ausracdbd01 multipathd: checker failed path 69:0 in map
> orabackup_hs
> Nov 21 13:47:09 ausracdbd01 kernel: device-mapper: multipath: Failing
> path 69:0.
> Nov 21 13:47:10 ausracdbd01 multipathd: checker failed path 65:192 in
> map ph1d
> Nov 21 13:47:10 ausracdbd01 kernel: device-mapper: multipath: Failing
> path 65:192.
> Nov 21 13:47:10 ausracdbd01 multipathd: checker failed path 65:224 in
> map limsd
> Nov 21 13:47:10 ausracdbd01 kernel: device-mapper: multipath: Failing
> path 65:224.
> Nov 21 13:47:10 ausracdbd01 multipathd: checker failed path 65:240 in
> map limsd_arch
> 

Can you attach the 'multipath -ll' output? Run the program before
you delete/add the LUNs and after, please.

How do you delete/add the LUNs? Are you re-using the LUN number, or are you
actually deleting a LUN, deleting the block device as well, and then
when adding (with a new LUN number higher than the deleted one), rescanning 
the SCSI host channel to get the new block device for the LUN?