SCSI

SCSI

Small Computer System Interface is a set of standards for physically connecting and transferring data between computers and peripheral devices. The SCSI standards define commands, protocols, and electrical and optical interfaces. SCSI is most commonly used for hard disks and tape drives, but it...

 target devices provide a number of SCSI log pages. These can be interrogated by a Log Sense command

SCSI Log Sense Command

The SCSI Log Sense command is used to obtain current data from log pages in a SCSI target device. The CDB structure for the Log Sense command is:The special parameter fields in the CDB have the following meaning:...

 and in some cases can be set by a Log Select command

SCSI Log Select Command

The SCSI Log Select command "provides a means for an application client to manage statistical information maintained by the SCSI target device about the target device or its logical units"...

. The Log Sense and Log Select commands include a 6-bit address field, allowing for 64 possible log pages. There is a standard map of log page addresses below. Note that any given SCSI device type will only support a subset of these log pages.

• 00h - supported log pages
• 01h - buffer over-run/under-run
• 02h - error counter (write)
• 03h - error counter (read)
• 04h - error counter (read reverse)
• 05h - error counter (verify)
• 06h - non-medium error
• 07h - last n error events
• 08h-2Fh - reserved
• 30h-3Eh - vendor-specific
• 3Fh - reserved