Parav Pandit wrote: > Hi, > > Few basic questions on sg driver: > > 1. Are there any hooks that low level HBA driver needs > to implement - for providing support for SG (SCSI > generic) driver? > Or SG always interacts with scsi_mod and it is > transparent to the HBA drivers? >>From the tldp How-to and sg.c it looks like it doesn't > directly talk with Low level HBA driver, but want to > confirm.
The sg driver talks to the scsi mid level (and the block layer strangely enough) but not directly to LLDs. > 2. Can applications talk with SCSI RAID controller > device (some targets exposes LUN-0 as controller) > through sg interface or it is only for storage > devices? The sg driver is useful for any SCSI device (logical unit) that is exposed by the scsi mid level. Apart from direct access (i.e. disk) devices that might include cd/dvd drives, tape drives, scsi enclosures, saf-te controllers (which have processor peripheral device type) and well known logical units. > 3. How is the mapping between /dev/sda /dev/sdb etc to > /dev/sg0 /dev/sg1 etc? > Is this information is accessible via procfs or sysfs > interface? In the lk 2.6 series the mapping can be found in sysfs (see lsscsi, specifically 'lsscsi -g'). In the sg3_utils package the sg_map utility shows the mapping. That may be helpful in the lk 2.4 series since there is no sysfs. Doug Gilbert - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
