Aboo Valappil wrote: > Hi All, > > Thanks for all your support for my previous posts. > > I have two questions. > > 1. Is it safe to assume that all the SG elements of request_buffer are > page aligned? (Except the first one and last one), I mean, it is always > multiple of pages? > > 2. What are situations reading a scsi disk (using dd ) cause a write to > the disk? When I read my virtual scsi disk using dd command, block > layer is generating lot of SCSI write, as well as reads. Any thoughts? > Besides this observation, everything is working fine. Aboo, A comment on your second point: to bypass the vagaries of the block layer caching with dd (or sg_dd) use 'iflag=direct' and/or 'oflag=direct' as required. There may be alignment constraints. Doug Gilbert - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
