Re: [PATCH] bcache: make stripe_size configurable and persistent for hardware raid5/6

[Martin K. Petersen]

Eric,

> Do you know if io_opt can be configured on scsi devices that do not
> have io_opt provided by the controller?  If so, or if it would be easy
> to add, then configuring io_opt at the scsi layer is probably a better
> option so subsystems besides bcache would benefit.

There is currently no way to do this in the SCSI sysfs interface.
However, io_opt is a queue_limits parameter. The appropriate location
for modification is blk-sysfs.c. We already allow overriding other block
device properties such as rotational, stable_writes, discards, max I/O
size, etc. I don't see any particular reason why we couldn't also permit
overriding the optimal I/O size.

-- 
Martin K. Petersen	Oracle Linux Engineering