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 diagnostic pages. These can be used by a Send Diagnostic command

SCSI Send Diagnostic Command

The SCSI Send Diagnostic command is used to instruct a target device to perform a self-test on a specific LUN. The CDB structure is:The special parameter fields in the CDB have the following meaning:*PF - Page Format:...

 to tell a target device to run a specialised self-test. The Receive Diagnostic Results

SCSI Receive Diagnostic Results Command

The SCSI Receive Diagnostic Results command is used to interrogate the results of a self-test. The self-test must have been triggered by a previous Send Diagnostic command which would have defined the self-test required. This is usually associated with one of the available diagnostic pages.The...

 command is used where the results from the self-test operation are non-trivial.

Most of the common SCSI devices such as disk-drives support only one or two diagnostic pages. SES

SCSI Enclosure Services

Most recent SCSI enclosure products support a protocol called SCSI Enclosure Services . The initiator can communicate with the enclosure using a specialised set of SCSI commands to access power, cooling, and other non-data characteristics.-SES devices:...

devices can support many diagnostic pages.

List of SCSI diagnostic pages

SCSI uses a one byte addressing scheme for diagnostic pages, allowing for a total 256 possible pages. There is a standard map of diagnostic page addresses shown below. Note that any given SCSI device type will only support a subset of these diagnostic pages.

Some diagnostic pages have two different meanings depending on whether they are being used for control purposes (Send Diagnostic command) or to interrogate status (Receive Diagnostic Results command). Those cases are shown as double entries in the table below using this convention: "control definition / status definition".

• 00h - list of supported diagnostic pages
• 01h - SES - configuration
• 02h - SES - enclosure control / enclosure status
• 03h - SES - help text
• 04h - SES - string out / string in
• 05h - SES - threshold out / SES threshold in
• 06h - SES - obsolete
• 07h - SES - element descriptor
• 08h - SES - short enclosure status
• 09h - SES - enclosure busy
• 0Ah - SES - additional element
• 0Bh - SES - subenclosure help text
• 0Ch - SES - subenclosure string out / SES subenclosure string in
• 0Dh - SES - supported SES diagnostic pages
• 0Eh - SES - download microcode control / SES download microcode status
• 0Fh - SES - subenclosure nickname control / SES subenclosure nickname status
• 10h-1Fh - SES - vendor-specific
• 20h-2Fh - SES - reserved
• 30h-3Eh - reserved
• 3Fh - used by the SCSI transport layer
• 40h - disk/optical - translate address
• 41h-7Fh - reserved
• 80h-FFh - vendor-specific