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Diffstat (limited to 'doc/sg_inq.8')
| -rw-r--r-- | doc/sg_inq.8 | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/doc/sg_inq.8 b/doc/sg_inq.8 index db591986..a0bfae94 100644 --- a/doc/sg_inq.8 +++ b/doc/sg_inq.8 @@ -1,4 +1,4 @@ -.TH SG_INQ "8" "March 2021" "sg3_utils\-1.46" SG3_UTILS +.TH SG_INQ "8" "June 2021" "sg3_utils\-1.47" SG3_UTILS .SH NAME sg_inq \- issue SCSI INQUIRY command and/or decode its response .SH SYNOPSIS @@ -492,6 +492,24 @@ pages (but not their contents) try: .PP sg_inq \-e /dev/sda .PP +In Linux, binary images of some important VPD page responses (e.g. 0, 80h +and 83h) are cached in files within the sysfs pseudo file system. Since +VPD pages hardly ever change their contents, decoding those files will +give the same output as probing the device with the added benefit that +decoding those files doesn't need root permissions. If /dev/sg3 is a disk +at 2:0:0:0 , then these three invocations should result in the same output: +.PP + sg_inq \-\-raw \-\-inhex=/sys/class/scsi_generic/sg3/device/vpd_pg83 +.PP + sg_inq \-rI /sys/class/scsi_generic/sg3/device/vpd_pg83 +.PP + sg_inq \-r \-I /sys/class/scsi_disk/2:0:0:0/device/vpd_pg83 +.PP +Without the \fI\-\-raw\fR option, the \fI\-\-inhex=FN\fR option would +expect the contents of those files to be hexadecimal. vpd_pg83 contains +the response (in binary) to the Device Identification VPD page whose page +number is 83h (i.e. hexadecimal). +.PP Some VPD pages can be read with the sg_inq utility but a newer utility called sg_vpd specializes in showing their contents. The sdparm utility can also be used to show the contents of VPD pages. |