On 06/04/2013 08:39 AM, Joe Lawrence wrote:

quoted

We should probably add Joe Lawrence to this thread.

Joe: basically it seems that the error behavior of md (at least raid10,
but probably raid1 as well) on WRITE SAME is wrong, and it causes the
RAID to abort.

Martin is probably the expert here (I had extended his initial WRITE SAME 
support in MD raid0 to raid1 and raid10), but I can try failing a WS cmd 
using our San Blaze emulator to see the fall out. 

Just curious, what type drives were in your RAID and what does
/sys/class/scsi_disk/*/max_write_same_blocks report?  If you have a spare 
drive to test, maybe you could try a quick sg_write_same command to see 
how the drive reacts?

The drives are SATA drives connected via mptsas.  max_write_same_blocks
show 65535.  Unfortunately the problems are rare enough that it didn't
pop up until the server was put in production, so I would like to avoid
experimenting on it as much as possible.

	-hpa