SCSI mode page

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SCSI target devices provide a number of SCSI mode pages. These can be interrogated by a MODE SENSE command and set by a MODE SELECT command. The MODE SENSE commands and the mode page formats include a 6-bit page code field, allowing for 64 possible mode pages. When the number of pages approached this limit, an eight-bit subpage code field was added. A description of many of these page codes is included below. Note that any given SCSI device type will only support a subset of the possible page codes, and some page codes may have different meanings for different devices.

List of SCSI mode page codes[edit]


Page/Subpage Code Description
00h/xxh Vendor specific
01h/00h Read-Write Error Recovery
02h/00h Disconnect-Reconnect - allows the initiator to tune SCSI bus performance
03h/00h Format Device (disk devices)
04h/00h Rigid Disk Geometry
05h/00h Flexible Disk
06h/00h Optical Memory
06h/00h RBC Device Parameters
07h/00h Verify Error Recovery
08h/00h Caching
0Ah/00h Control - tagged queuing, extended contingent allegiance, asynchronous event notification, and error logging
0Ah/01h Control Extension - timestamp, asymmetric logical unit access, initial command priority, maximum sense data length
0Bh/00h Medium Types Supported
0Ch/00h Notch and Partition
0Dh/00h CD Device Parameters
0Eh/00h CDROM Audio Control
0Eh/01h Target Device (Automation/Drive Interface)
0Eh/02h DT Device Primary Port parameters (Automation/Drive Interface devices)
0Eh/03h Logical Unit parameters (Automation/Drive Interface devices)
0Eh/04h Target Device Serial Number (Automation/Drive Interface devices)
10h/00h Device Configuration
11h/00h Medium Partition (1)
14h/00h Enclosure Services Management
15h/00h Extended
16h/00h Extended Device-Type Specific
18h/00h Protocol-Specific Logical Unit
19h/00h Protocol-Specific Port
1Ah/00h Power Conditions
1Ah/01h Power Control
1Bh/00h LUN Mapping
1Ch/00h Informational Exceptions Control
1Ch/01h Background Control
1Ch/02h Logical Block Provisioning
1Dh/00h Element Address Assignment (media changer devices)
1Eh/00h Transport Geometry Parameters (media changer devices)
1Fh/00h Device Capabilities (media changer devices)
20h-29h Vendor specific
2Ah/xxh Device-type specific
2Ah/00h CD Capabilities and Mechanical Status
3Fh/xxh return all pages and/or subpages (valid only for a MODE SENSE command)
xxh/FFh return all subpages (valid only for a MODE SENSE command)


  1. ^ "SCSI Primary Commands - 4 (SPC-4)" (PDF). Retrieved 2021-12-07.