SDPARM(8)

🦋 NAME 🦋

sdparm — access SCSI modes pages; read VPD pages; send simple SCSI commands.

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🌸 SYNOPSIS 🌸

sdparm [--all] [--dbd] [--examine] [--flexible] [--get=STR] [--hex]
[--long] [--num-desc] [--out-mask=OM] [--page=PG[,SPG]] [--quiet]
[--readonly] [--six] [--transport=TN] [--vendor=VN] [--verbose] DEVICE
[DEVICE...]

sdparm [--clear=STR] [--defaults] [--dummy] [--flexible]
[--page=PG[,SPG]] [--quiet] [--readonly] [--save] [--set=STR] [--six]
[--transport=TN] [--vendor=VN] [--verbose] DEVICE [DEVICE...]

sdparm --command=CMD [--hex] [--long] [--readonly] [--verbose] DEVICE
[DEVICE...]

sdparm --inquiry [--all] [--examine] [--flexible] [--hex] [--num-desc]
[--page=PG[,SPG]] [--quiet] [--readonly] [--transport=TN] [--verbose]
DEVICE [DEVICE...]

sdparm --enumerate [--all] [--inquiry] [--long] [--page=PG[,SPG]]
[--transport=TN] [--vendor=VN]

sdparm --inhex=FN [--all] [--flexible] [--hex] [--inquiry] [--long]
[--pdt=DT] [--raw] [--six] [--transport=TN] [--vendor=VN] [--verbose]

sdparm --wscan [--verbose]

sdparm [--help] [--version]

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💅 DESCRIPTION 💅

Okay bestie, gather round, because this little utility is doing the most and honestly? Iconic. sdparm fetches and potentially changes SCSI device mode pages — think like, a disk, you know? Inquiry data is also on the menu, and yes, that includes Vital Product Data (VPD) pages. 🦋 And it doesn't stop there: it can also fire off commands for starting and stopping the medium, loading and unloading the medium, plus a whole bunch of other housekeeping functions. Main character energy fr fr. ✨

Now, the synopsis above has eight whole vibes and you need to know which is which:

• The first invocation is for accessing (i.e. reading) mode page fields held on the DEVICE. 👀
• The second form is for changing mode page fields held on the DEVICE.
• The third form is for executing some simple SCSI commands.
• The fourth form (i.e. the '--inquiry ... DEVICE' form) is for fetching and decoding VPD pages from the given DEVICE.
• The --enumerate form is for listing out mode or VPD field data held by this utility (and if a DEVICE is given then it is ignored — she said not today 💀).
• The --inhex=FN form decodes mode or VPD response data provided in the named file (or from stdin if FN=- is given); that data may either be in hexadecimal or binary.
• The second last form is for Windows only and lists the available storage device names; see the OPTIONS entry for --wscan.
• The final form is to provide command line help or the version number (and date) of this utility.

If no options (other than DEVICE) are given then a selection of common mode page fields for that device are listed. Cute, right? And if the --long option is also given then a description of the fields is placed on the right of each line. If the --all option is given then all known mode page fields for that device are listed. Individual fields can be displayed with the --get=STR option (e.g. '--get=WCE' to fetch the state of the Writeback Cache Enable field — slay 💅).

This utility completes with an exit status of 0 when successful. For other values see the EXIT STATUS section below.

One or more DEVICE arguments can be given. The utility will essentially apply the given options to each DEVICE in the list. If a error is detected, it is noted and the utility continues — she's resilient like that. 🫶 Error value 5 (file open or close problem) is treated as lower priority when other errors are detected. The exit status is the most recently detected error value (excluding error value 5 if other errors have been detected). If all actions succeed the exit status is zero.

By default this utility shows mode pages that are common to all transport protocols. These are termed as "generic" mode pages. If there is no match on a generic mode page name or field then those pages specific to the SAS transport are checked. Transport protocol specific mode pages are selected with the --transport=TN option. See the TRANSPORT section below. Vendor specific mode pages are selected with the --vendor=VN option. See the VENDORS section below.

Although originally for SCSI disks (or storage devices that appear to the OS as SCSI disks) many of the mode pages are for other SCSI device types. These include CD/DVD players that use the ATAPI (or any other) transport, SCSI tapes drives and SCSI enclosures. Versatile queen. 👑

When the --inquiry option is given without a page number then the Device Identification VPD page (page number 0x83) is requested and if found it is decoded and output. If no page number is given and the --all option is given then a list of VPD page names (but not their contents) supported by the DEVICE is output. When both the --inquiry and --page=PG options are given then the VPD page can be specified as an abbreviation (e.g. "sp" for the SCSI ports VPD page) or numerically (e.g. "0x88"). If a VPD page is returned by the DEVICE but sdparm cannot decode it or the --hex option is given then it is output in hex.

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🎀 OPTIONS 🎀

Mandatory arguments to long options are mandatory for short options as well. If an option takes a numeric argument then that argument is assumed to be decimal unless otherwise indicated (e.g. with a leading "0x" or a trailing "h"). The options are in alphabetical order, based on the long option name. 💖

• -a, --all — output all recognized fields for the device type (e.g. disk) of the DEVICE. Without this option (or the --page=PG[,SPG] option) the default action is to output a relatively small number of commonly used fields from different pages. When a specific (mode) page number is given with the --page=PG[,SPG] option then all the fields of that page are output (irrespective of the setting of this option). For this option's action when used with the --enumerate option see the ENUMERATE section below.

When used together with the --inquiry option and a DEVICE, the Supported VPD Pages VPD page [0x0] is output. When this option is used twice (short form: '-iaa') then all VPD pages (listed in the Supported VPD Pages VPD page) are output.

By default --inhex=FN will only decode the first mode page found in FN. With this option, more mode pages will be decoded if present. When --transport=TN or --vendor=VN is also given then if a given mode page is not defined for that transport or vendor, then it is decoded as a generic mode page.

• -c, --clear=STR — In its simplest form STR contains a field acronym_name or a field numerical descriptor. In the absence of an explicit value argument (e.g. '--clear=WCE=1'), the field has its value cleared to zero. See the PARAMETERS section below.
• -C, --command=CMD — Perform given CMD. See section below on COMMANDS. To enumerate supported commands use '-e -C x' (using any CMD name, valid or otherwise). 🎀
• -B, --dbd — disable block descriptors. This is a bit in MODE SENSE cdbs that rarely needs to be set. One known case is a MODE SENSE 6 issued to a Reduced Block Commands (RBC) device where the RBC standard says it shall be set. (iykyk 🫠)
• -D, --defaults — sets the given mode page to its default values. Requires the --page=PG[,SPG] option to be given to specify the mode page. To make the default mode page values also the saved mode page values, use the --save option as well.

when this option is used twice, the current values in all modes pages are reverted to their defaults. If the --save option is given as well, then the current and saved values in all modes pages are reverted to their defaults. This feature uses the RTD bit in the MODE SELECT command which was added in draft SPC-5 revision 11.

• -d, --dummy — when set inhibits changes being placed in the DEVICE's mode page. Instead the mode data that would have been sent to a MODE SELECT command, is output in ASCII hex to the console. This option is mainly for testing. 🧪
• -e, --enumerate — lists out descriptive information about the pages and fields known to this utility. Ignores the DEVICE argument and other options apart from the --all, --inquiry, --long, --page=PG[,SPG], --transport=TN and --vendor=VN. If --enumerate is given without other options then the known (generic) mode pages are listed. See the ENUMERATE section below.
• -E, --examine — for mode pages only those with known field names are probed when the --all option is given. For VPD pages only those pages listed in "Supported VPD pages page" are decoded. In both cases some pages may be missed. With this option (i.e. --examine) all mode and VPD pages can be probed.

For mode pages, this option will probe all mode pages from page number 0x0 to 0x3e. To probe mode subpages give a mode page number with --page=PG and then all subpages (from 0x0 to 0xfe) are probed.

For VPD pages, use this option with --inquiry. This will cause all VPD pages from 0x0 to 0xbf to be probed by default. A sequence of VPD pages can be probed with --page=PG[,SPG] in which case VPD pages from PG (lower number) to SPG (high number) inclusive are probed. Vendor specific VPD pages run from 0xc0 to 0xff and can be probed by setting SPG from 0xc0 to 0xff. 🔍

• -f, --flexible — Some devices, bridges and/or drivers attempt crude transformations between mode sense 6 and 10 byte commands without correctly rebuilding the response. This will cause the response to be mis-interpreted (usually with an error saying the response is malformed). With this option, the length of the response is checked, and if it looks wrong, various corrections are attempted. This option will also allow mode pages that don't belong to the current device's peripheral type to be listed. 💀→🦋
• -g, --get=STR — In its simplest form STR contains a field acronym_name or a field numerical descriptor. The field is fetched from mode page. See the PARAMETERS section below. The --long and --hex options effect the output format. Also if a value of "1" is given (e.g. '--get=WCE=1') only the current value is output (i.e. not the change mask, the default value and the saved value).
• -h, --help — output the usage message then exit.

okay bestie we made it to -h and there are so many more options still coming 👀 keep scrolling, this page is long and it's giving ✨encyclopedia✨ 💖

• -H, --hex — bestie, sometimes you don't want the decode, you just want the raw truth. This prints mode (or VPD) pages out in hex instead of trying to decode them. When you pair it with the --get=STR option, the matching current, changeable, default and saved values come out in hex, prefixed by "0x" and space separated. Give a value of "1" with --get=STR (like '--get=WCE=1') and only the current value gets printed, in hex, prefixed by "0x". Give a value of "2" and only the current value is output as a (signed) integer. You can stack this option multiple times (e.g. '-HH'). Super useful with the ATA Information VPD page, which usually spits out its IDENTIFY (PACKET) DEVICE response in 16 bit hex words — with '-HH' it outputs that response in hex bytes, and with '-HHH' it outputs the same response in a format suitable for 'hdparm --Istdin' to decode. Mode page output with the '-HHH' option is suitable for a later invocation of sdparm with the --inhex=FN option. layers, queen 💅
• -i, --inquiry — outputs a VPD page that lives inside the response of a SCSI INQUIRY command sent to DEVICE. No --inquiry? Then the default action is mode pages, periodt. If you give --inquiry without --page=PG[,SPG], the device identification VPD page (0x83) gets decoded and output. And if you give this option and --all, then the supported VPD pages page (0x0) is decoded and output. choose your own adventure ✨
• -I, --inhex=FN — FN should be a file name (or '-' for stdin) holding ASCII hexadecimal (or binary) that represents the response to MODE SENSE(10). If --six is also given, then the response from MODE SENSE(6) is assumed instead. Quick anatomy lesson: a MODE SENSE response has a mode parameter header, then 0 or more block descriptors, followed by one or more mode pages. heads up: this utility only decodes the first mode page unless the --all option is given. To decode a mode page the peripheral device type is often needed, and you can supply it with the --pdt=DT option. If --pdt=DT isn't given, then a mode page found in two device type standards (e.g. SBC and SSC) may get decoded twice. If --inquiry is given, then FN is interpreted as the response data of a single VPD page.
  • The hexadecimal in FN should be arranged as 1 or 2 digits representing a byte, each of which is whitespace or comma separated. Anything from and including a hash mark to the end of line is ignored. And if the --raw option is given, then FN is treated as binary. 🍓
• -l, --long — outputs extra information. For mode page fields, a description (with units if applicable) is output to the right. Use it twice and, for some fields, more info about its values appears on one or more following lines, each prefixed by a tab character. For usage with --enumerate, see the ENUMERATE section below. 👀
  • When this option is used along with --command=capacity, the READ CAPACITY(16) is sent to the DEVICE and, if successful, its extended response is output. receipts!
• -n, --num-desc — for a mode page that can have descriptors, this outputs the number of descriptors for the given page on the DEVICE. Otherwise 0 is output. short and sweet
• -o, --out-mask=OM — OM is a bit mask for mode page selections that will be printed/output. The 0x1 value is for the 'current' values, 0x2 is for the 'changeable' values, 0x4 is for the 'default' values and 0x8 is for the 'saveable' values. The default value is 0xf (i.e. the OR of all four values set). This option is useful for limiting the amount of output with the '-HHH'. 🎀
• -p, --page=PG[,SPG] — supply the page number (PG) and optionally the sub page number (SPG) of the mode (or VPD) page to fetch. These numbers are interpreted as decimal unless prefixed with "0x" or a trailing. Sub page numbers are only valid for mode pages (not VPD pages). Alternatively, an abbreviation for a page can be given (see next entry). vibe check passed
• -p, --page=STR — a two or three letter abbreviation for a page can be given. Known mode page abbreviations are checked first, followed by known VPD page abbreviations. For example '--page=ca' matches the caching mode page. If no match is found then an error is issued and a list of possibilities in the current context is given (so '-p x' can be quite useful, iykyk). If the STR matches a known VPD page abbreviation, then the --inquiry option is assumed. For usage with --enumerate, see the ENUMERATE section below. 🔥
• -P, --pdt=DT — this option is only active when the --inhex=FN option is given. DT is the peripheral Device Type, a value between 0 and 31, and can be found in the response to the INQUIRY command. The default value is -1 (which may also be given for DT) and it is interpreted as SPC (i.e. common mode pages) or as a wild card. If available, this option should be supplied with the --inhex=FN option. no cap
• -q, --quiet — suppresses output of the device name followed by the vendor, product and revision strings fetched from an INQUIRY response. Without this option such a line is typically the first line output by sdparm. It also reduces output from the device identification VPD page, typically to one line (or none) for each of di_lu, di_port, di_target and di_asis.
  • Use it twice and, additionally, mode page output suppresses the changeable, default and saved values that are usually shown in braces, if available. shhh 🤫
• -r, --readonly — overrides other logic to open DEVICE in read-only mode. The default setting of the open read-only/read-write mode depends on the operation requested (e.g. a --set=STR operation by default will try a read-write mode open on DEVICE). This option may be useful if a command is being sent to an ATA disk via a SCSI command set. For example in Linux '-C stop' may require this option to stop an ATA disk being restarted immediately. protective queen energy 👑
• -R, --raw — only active when used with the --inhex=FN option. When given, the file FN is interpreted as binary; the default action (i.e. when this option is not given) is to interpret FN as ASCII hexadecimal. 🦋
• -S, --save — when a mode page is being modified (by using the --clear=STR and/or --set=STR options), the default action is to modify only the current values mode page. When this option is given, the corresponding value(s) in the saved values mode page are also changed. The next time the device is power cycled (or reset), the saved values mode page becomes (i.e. is copied to) the current values mode page. This option sets the SP field in the MODE SELECT command. See the NOTES section below. 💾
• -s, --set=STR — in its simplest form, STR contains a field acronym_name or a field numerical descriptor. In the absence of an explicit value, each acronym_name has its value set to (all) ones. This means a 16 bit field will be set to 0xffff which is 65535 in decimal. Alternatively each acronym_name or numerical descriptor may be followed by "=<n>" where <n> is the value to set that field to. See the PARAMETERS section below. glow up your fields ✨
• -6, --six — the default action of this utility is to issue MODE SENSE and MODE SELECT SCSI commands with 10 byte cdbs. When this option is given, the 6 byte cdb variants are used. RBC and old SCSI devices may need this option. This utility outputs a suggestion to use this option if the SCSI status indicates that the 10 byte cdb variant is not supported.
  • The SPC-4 standard (and SPC-5 drafts) include a note stating that implementers migrate away from the SCSI MODE SELECT(6) and MODE SENSE(6) commands in favour of the 10 byte variants (e.g. MODE SEMSE(10)). yes, it says SEMSE, we don't make the rules 💀
• -t, --transport=TN — Specifies the transport protocol where TN is either a number in the range 0 to 15 (inclusive) or an abbreviation (e.g. "fcp" for the Fibre Channel Protocol). Some transports accept multiple abbreviations, for example srp (SCSI RDMA Protocol) and ib (short for InfiniBand) both are accepted for transport protocol 0x4. Also both upper and lower case are accepted, so iscsi and iSCSI are accepted for transport protocol 0x5. One way to list available transport protocols numbers and their associated abbreviations is to give an invalid transport protocol name such as '-t x'; another way is '-e -l'. N.B. The --all option may still be needed to show all available fields. 🚀
• -M, --vendor=VN — Specifies the vendor (i.e. manufacturer) where VN is either a number (0 or more) or an abbreviation (e.g. "sea" for Seagate disk vendor specific). For tape drives "lto5" and "lto6" are treated as vendors. One way to list the available vendor numbers and their associated abbreviations is to give an invalid vendor number such as '-M x'; another way is '-e -l'.
  • This option only effects mode page decodes, not VPD pages. For vendor specific VPD pages see the sg_vpd utility. different tool, different slay
• -v, --verbose — increases the level of verbosity, (i.e. debug output). In some cases more decoding is done (e.g. fields within a standard INQUIRY response). spill the tea, device 🫖
• -V, --version — prints the version string and then exits. short king
• -w, --wscan — this option is available in Windows only. It lists storage device names and the corresponding volumes, if any. When used twice it adds the "bus type" of the closest transport (e.g. a SATA disk in a USB connected enclosure has bus type Usb). When used three times a SCSI adapter scan is added. When used four times only a SCSI adapter scan is shown. See examples below and the "Win32 port" section in the README file. 🪟

✨ NOTES ✨

okay bestie, the reference doc we're using to interpret mode and VPD pages (and that standard INQUIRY response) is T10/BSR INCITS 502 Revision 17 (that's SPC-5, 19 September 2017) and you can find it at http://www.t10.org. Anything in the standard INQUIRY response output that's obsolete or reserved gets shown in brackets. 📎

We also pull from recent drafts of other T10 documents: SBC-4 (disks), SSC-5 (tapes), SPL-5 (SAS transport) and SAT-4 (SCSI to ATA Translation).

A mode page where nobody knows the abbreviation (hi, vendor specific mode pages 👋) can still be listed in hexadecimal — just use the option combo --page=PG --hex.

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Numbers you feed into sdparm (like in the command line arguments) are assumed decimal unless there's a hexadecimal indicator. And a hex indicator is either a leading 0x or 0X (the C language convention, iconic) or a trailing h or H (the convention used at www.t10.org). BUT — special case — with --page= either a string or number is expected, so hex numbers like ch (12) should be prefixed by a zero, e.g. 0ch. ✨

The SPC-4 draft (rev 2) says that devices which implement no distinction between current and saved pages can return an error (ILLEGAL REQUEST, invalid field in cdb) if the SP bit (which corresponds to the --save option) is _not_ set. In those cases you gotta give the --save option. no cap.

If you give --save but the existing mode page says (via its PS bit) that the page is not saveable, then this utility generates an error message. And that message suggests you try again without --save. so helpful of it 💅

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The device identification VPD page (acronym_name "di") can potentially contain a LOT of diverse designators, so there's several associated acronyms available:

• "di_lu" — designators associated with the addressed logical unit
• "di_port" — designators associated with the target port (which the command arrived via)
• "di_target" — designators associated with the target device

When you use "di" the designators get grouped by lu, then port, then target device. And if you wanna see all designators decoded in the exact order they appear in the VPD page, use "di_asis". 🦋

Only the VPD pages defined by t10.org get decoded by this utility. SPC-4 sets aside VPD page codes from 0xc0 to 0xff (inclusive) for vendor specific pages — some of which are decoded in the sg_vpd utility.

Wanna see all VPD pages a DEVICE supports? sg_vpd --all. periodt.

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In the linux kernel 2.6 and 3 series, any device node that understands a SCSI command set (think SCSI disks and CD/DVD drives) may be specified. More precisely: the driver that "owns" the device node must support the SG_IO ioctl. In the lk 2.4 series, only SCSI generic (sg) device nodes support the SG_IO ioctl. BUT in the lk 2.4 series, other SCSI device nodes get mapped within this utility to their corresponding sg device nodes. So if there's a SCSI disk at /dev/sda then sdparm /dev/sda will work in both the lk 2.4 series and later. However, if there's an ATAPI cd/dvd drive at /dev/hdc then sdparm /dev/hdc will only work in the lk 2.6 series and later. 🙈

In the Linux 2.6 and 3 series, especially with ATA disks, using sdparm to stop (spin down) a disk may not be sufficient and other mechanisms will start the disk again some time later. The user might additionally mark the disk as "offline" with:

echo offline > /sys/block/sda/device/state

where sda is the block name of the disk. To restart the disk, "offline" can be replaced with "running". 🔥

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🌸 PARAMETERS 🌸

In their simplest form the --clear=, --get= and --set= options (or their short forms) take an acronym_name such as "WCE". So:

• '--get=WCE' — the value of "Writeback Cache Enable" in the caching mode page gets fetched
• '--set=WCE' — that bit gets set (to one)
• '--clear=WCE' — that bit gets cleared (to zero)

When an acronym_name is given, the mode page is imputed from that acronym_name (like, WCE lives in the caching mode page). iykyk.

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Instead of an acronym_name, you can describe a field within a mode page numerically with a <start_byte>:<start_bit>:<num_bits> tuple. Here's what those are:

• <start_byte> — origin 0, within the mode page
• <start_bit> — 0 to 7 inclusive
• <num_bits> — 1 to 64 inclusive

For example, the low level representation of the RCD bit (the "Read Cache Disable bit in the caching mode page) is "2:0:1". The <start_byte> can optionally be given in hex (e.g. '--set=0x2:0:1' or '--set=2h:0:1'). With this form, the --page= option is required to establish which mode page is to be used. 💅

Either form can optionally be followed by "=<val>". By default <val> is decimal but can be given in hex in the normal fashion. Some examples for you bestie: '--set=2h:0:1=1h' and '-s MRIE=0x3'.

Here's the tea on defaults:

• When the acronym_name or numeric form following --clear= is not given an explicit '=<val>', the value defaults to zero.
• When the acronym_name or numeric form following --set= is not given an explicit '=<val>', the value defaults to "all ones" (i.e. as many as <num_bits> permits).

So '--clear=WCE' and '--clear=WCE=0' mean the same thing: clear Writeback Cache Enable, or put more simply — turn off the writeback cache. 🎀

Multiple fields within the same mode page can be changed by giving a comma separated list of acronym_names and/or the numerical form. Like: '--set=TEST,MRIE=6'. slay.

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Some mode pages have multiple descriptors. They typically have a fixed header section at the start of the mode page that includes a field containing the number of descriptors that follow. Following the header is a variable number of descriptors. An example is the SAS Phy Control and Discover mode page. An acronym_name may include a trailing '.<num>' where <num> is a descriptor number (origin 0).

So check it:

• '-t sas -g PHID.0' and '-t sas -g PHID' will yield the phy identifier of the first descriptor of the above mode page
• '-t sas -g PHID.1' will yield the phy identifier of the second descriptor

✨ iconic behavior honestly.

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👑 ENUMERATE 👑

The --enumerate option essentially dumps out static information held by this utility. A list of --enumerate variants and their actions follows. For brevity, subsequent examples of options are shown in their shorter form.

--enumerate          list generic mode page information
-e --all             list generic mode page contents
                     (i.e. parameters)
-e --page=rw         list contents of read write error
                     recovery mode page
-e --inquiry         list VPD pages this utility can decode
-e --long            list generic mode pages, transport
                     protocols, mode pages for each
                     supported transport protocol and
                     supported commands
-e -l --all          additionally list the contents of
                     each mode page
-e --transport=fcp   list mode pages for the fcp
                     transport protocol
-e -t fcp --all      additionally list the contents of
                     each mode page
-e --vendor=sea      list vendor specific mode pages for
                     "sea" (Seagate)
-e -M sea --all      additionally list the contents of vendor
                     specific mode pages for "sea" (Seagate)
-e -p pcd -l         list contents of SAS phy control and
                     discovery mode page plus (due to "-l")
                     some descfriptor format information

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When known mode pages are listed (via the --enumerate option) each line starts with a two or three letter abbreviation. Then comes the page number (in hex prefixed by "0x") optionally followed by a comma and the subpage number. Finally the descriptive name of the mode page (e.g. as found in SPC-4) is output. 🌈

When known parameters (fields) of a mode page are listed, each line starts with an acronym (indented a few spaces). This will match (or be an acronym for) the description for that field found in the (draft) standards. Next are three numbers, separated by colons, surrounded by brackets. These are:

• the start byte (in hex, prefixed by "0x") of the beginning of the field within the mode page
• the starting bit (0 through 7 inclusive)
• the number of bits

Then the descriptive name of the parameter (field) is given. If appropriate, the descriptive name includes units (e.g. "(ms)" means the units are milliseconds). Adding the '-ll' option will list information about possible field values for selected mode page parameters. 😭 so much info, love that for us.

Mode parameters where the num_bits is greater than 1 can be viewed as unsigned integers. Often 16 and 32 bit fields are set to 0xffff and 0xffffffff respectively (all ones) which usually has a special meaning (see drafts). This utility outputs such values as "-1" to save space (rather than their unsigned integer equivalents). And "-1" can also be given as the value to a mode page field acronym — e.g. '--set=INTT=-1' sets the interval timer field in the Informational Exceptions control mode page to 0xffffffff. 💀

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🛸 TRANSPORTS 🛸

SCSI transport protocols are a relatively specialized area that can be safely ignored by the majority of users. not me though, I know my stuff.

Some transport protocols have protocol specific mode pages. These are usually:

• the disconnect-reconnect (0x2)
• the protocol specific logical unit (0x18)
• the protocol specific port (0x19)

In some cases the latter mode page has several subpages. The most common transport protocol abbreviations likely to be used are "fcp", "spi" and "sas".

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Many of the field names are re-used in the same position, so the acronym_name namespaces have been divided between generic mode pages (i.e. when the --transport= option is _not_ given) and a namespace for each transport protocol. A LUPID field from the protocol specific logical unit (0x18) mode page and the PPID field from protocol specific port (0x19) mode page are included in the generic modes pages — this is so the respective (transport) protocol identifiers can be seen. In most cases the user will know what the "port" transport is (i.e. the same transport as the HBA in the computer) but the logical unit's transport could be different. 🧚

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🍓 VENDORS 🍓

SCSI leaves a LOT of space for vendor specific information. Often this is described in product manuals. The --vendor=VN (or -M=VN) option allows known vendor specific mode pages to be examined and/or modified by acronym. 💖

In this utility the syntax and semantics of vendor specific mode pages is very similar to those of transport protocol specific mode pages. Both cannot be specified together. Vendor specific modes pages can still be accessed numerically (as shown at the end of the EXAMPLES section). 🫶

💖 COMMANDS 💖

Okay bestie, the command option sends a SCSI command to the DEVICE. If the command fails then this is reflected in the non-zero exit status. Wanna know more about the error? Use the -v option. Periodt. 💅

• capacity — sends a READ CAPACITY(10) command (valid for disks and cd/dvd media) by default. If successful yields "blocks: " [the number of blocks], "block_length: " [typically either 512 or 2048] and "capacity_mib: " [capacity in MibiBytes (1048576 byte units)]. ✨

If the number of blocks is too large to fit in the 4 byte field provided by READ CAPACITY(10) or, the --long option is given, then the READ CAPACITY(16) command is sent. If the --long option is given, then the extra fields found in the READ CAPACITY(16) response are output. No cap.

• eject — stops the medium and ejects it from the device. Note that ejection (by command or button) may be prevented in which case the unlock command may be useful in extreme cases. Typically only appropriate for cd/dvd drives and disk drives with removable media. Objects if sent to another peripheral device type (but objection can be overridden with -f option). 😤
• load — loads the medium and starts it (i.e. spins it up). See eject command for supported device types. 🎀
• profile — lists the various formats that a CD/DVD/HD-DVD/BD drive supports. These are called "profiles" in the MMC standard. The profiles are listed one per line. If media is in the drive then the profile that matches the media (if any) has an "*" to the right of the line. 🌈
• ready — sends the "Test Unit Ready" SCSI command to the DEVICE. No error is reported if the device will respond to data requests (e.g. READ) in a reasonable timescale. For example, if a disk is stopped then it will report "not ready". All devices should respond to this command. 🫶
• sense — sends a REQUEST SENSE command. It reports a hardware threshold exceeded, warning or low power condition if flagged. If a progress indication is present (e.g. during a format) then it will be output as a percentage. Yields a process status of 0 if the command succeeds and the sense key is 0; else yields 1. The --quiet option can be used to lessen output, and --hex to output sense data in hex. 👑
• speed=SPEED — permits the speed of a CD, DVD, HD_DVD or BD disc in a drive to be set (or at least influenced). It has this format: --command=speed=SPEED where SPEED is in kilobytes per second. In this case a kilobyte is 1000 bytes. The "times one" speed for a CD is 176.4 kB/s, for a DVD is 1350 kB/s and for both HD-DVD and BD it is 4500 kB/s. If SPEED is zero then the drive is set to the speed that it considers gives optimal performance. This command sends a SET STREAMING multi-media command (MMC) to the drive. The EXACT bit is clear so the drive will round the given SPEED as necessary. The command is designed to control read speed; setting write speed should be left to "burning" programs. 🔥
• start — starts the medium (i.e. spins it up). Harmless if medium has already been started. See eject command for supported device types. If the DEVICE is an ATA disk in Linux the --readonly option may be required. ⭐
• stop — stops the medium (i.e. spins it down). Harmless if medium has already been stopped. See eject command for supported device types. If the DEVICE is an ATA disk in Linux the --readonly option may be required. See the NOTES section above. 💀
• sync — sends a SYNCHRONIZE CACHE command. The device should flush any data held in its (volatile) buffers to the media. 🦋
• unlock — tells a device to allow medium removal. It uses the SCSI "prevent allow medium removal" command. This is desperation stuff, possibly overriding a prevention applied by the OS on a mounted file system. The "eject" utility (from the "eject" package) is more graceful and should be tried first. This command is only appropriate for devices with removable media. 🙈

For loading and ejecting tapes the mt utility should be used (i.e. not these commands). The ready command is valid for tape devices. 🍓

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🌈 EXAMPLES 🌈

Wanna list the common (generic) mode parameters of a disk? Say less:

sdparm /dev/sda

To list the designators within the device identification VPD page of a disk:

sdparm --inquiry /dev/sda

To see all parameters for the caching mode page:

sdparm --page=ca /dev/sda

To see all parameters for the caching mode page with parameter descriptions to the right:

sdparm --page=ca --long /dev/sda

To get the WCE values (current changeable default and saved) in hex:

sdparm -g WCE -H /dev/sda
0x01 0x00 0x01 0x01

To get the WCE current value in hex:

sdparm -g WCE=1 -H /dev/sda
0x01

To set the "Writeback Cache Enable" bit in the current values page:

sdparm --set=WCE /dev/sda

To set the "Writeback Cache Enable" bit in the current and saved values page:

sdparm --set=WCE --save /dev/sda

To set the "Writeback Cache Enable" and clear "Read Cache Disable":

sdparm --set=WCE --clear=RCD --save /dev/sda

The previous example can also by written as:

sdparm -s WCE=1,RCD=0 -S /dev/sda

To re-establish the manufacturer's defaults in the current and saved values of the caching mode page:

sdparm --page=ca --defaults --save /dev/sda

If an ATAPI cd/dvd drive is at /dev/hdc then its common (mode) parameters could be listed in the lk 2.6 and 3 series with:

sdparm /dev/hdc

If there is a DVD in the drive at /dev/hdc then it could be ejected in the lk 2.6 and 3 series with:

sdparm --command=eject /dev/hdc

If the ejection is being prevented by software then that can be overridden with:

sdparm --command=unlock /dev/hdc

One disk vendor has a "Performance Mode" bit (PM) in the vendor specific unit attention mode page [0x0,0x0]. PM=0 is server mode (the default) while PM=1 is desktop mode. Desktop mode can be set (both current and saved values) with:

sdparm --page=0 --set=2:7:1=1 --save /dev/sda

The resultant change can be viewed in hex with the --hex option as there are no acronyms for vendor extensions yet. The PM bit is now covered by vendor specific mode pages and the above can also be accomplished with:

sdparm --vendor=sea --set=PM --save /dev/sda

What follows are some examples from Windows using the '--wscan' option. The idea is to list the storage device names on the system that might be invoked by other uses of sdparm.

# sdparm --wscan
PD0     [C]     FUJITSU   MHY2160BH         0000
PD1     [DF]    WD        2500BEV External  1.05  WD-WXE90
CDROM0  [E]     MATSHITA DVD/CDRW UJDA775  CB03

So 'sdparm -a CDROM0' and 'sdparm -a E' will show all the (known) mode page fields for the Matshita DVD/CD drive. By using the '--wscan' option twice, the bus type (as seen by the OS) is added to the output:

# sdparm -ww
PD0     [C]     <Ata  >  FUJITSU   MHY2160BH         0000
PD1     [DF]    <Usb  >  WD        2500BEV External  1.05  WD-WXE90
CDROM0  [E]     <Atapi>  MATSHITA DVD/CDRW UJDA775  CB03

And the pattern continues to add a SCSI adapter scan. This may be useful if there are specialized storage related devices (e.g. a SES device in an enclosure) but does add much extra information in this case.

# sdparm -www
PD0     [C]     <Ata  >  FUJITSU   MHY2160BH         0000
PD1     [DF]    <Usb  >  WD        2500BEV External  1.05  WD-WXE90
CDROM0  [E]     <Atapi>  MATSHITA DVD/CDRW UJDA775  CB03

SCSI0:0,0,0   claimed=1 pdt=0h  FUJITSU   MHY2160BH         0000
SCSI1:0,0,0   claimed=1 pdt=5h  MATSHITA  DVD/CDRW UJDA775  CB03

💅 EXIT STATUS 💅

Okay bestie, listen up, because if you're writing a script that calls sdparm you need this section. The exit status tells you success (0) or failure (1 or more). And here's the tea: some of the lower values literally correspond to the SCSI sense key values. So it's giving two-for-one. The values are:

• 0 — success 💖
• 1 — syntax error. That's illegal command line options, options with bad arguments, or a combination of options that is just not permitted. We don't do that here.
• 2 — the DEVICE is reporting it's not ready for the operation you requested. It might be in the process of becoming ready (think: spinning up but not at speed yet), so the utility might work if you just wait a sec. Give it a minute, bestie.
• 3 — the DEVICE reports a medium or hardware error (or a blank check). Like, if you try to read a corrupted block on a disk, this is the value you get.
• 5 — the DEVICE reports an "illegal request" with an additional sense code that isn't "invalid operation code". Usually this means a supported command with a field set that requests an unsupported capability. And for commands that need a "service action" field, this value can mean the command just isn't supported.
• 6 — the DEVICE reports a "unit attention" condition. Usually this means something unrelated to your requested command happened (like a device reset) potentially before the current SCSI command was even sent. Your requested command was not executed by the device. Also note: unit attention conditions are usually only reported once by a device. One and done.
• 7 — the DEVICE reports a "data protect" sense key. Some mechanism has blocked writes (or possibly all access to the media). Ouch.
• 9 — the DEVICE reports an illegal request with an additional sense code of "invalid operation code", which means it doesn't support the requested command. Not personal, it just can't.
• 10 — the DEVICE reports a "copy aborted". Another command or device problem stopped a copy operation. The EXTENDED COPY family of commands (including WRITE USING TOKEN) may return this sense key.
• 11 — the DEVICE reports an aborted command. In some cases aborted commands can be retried immediately (like if the transport aborted the command due to congestion).
• 14 — the DEVICE reports a miscompare sense key. VERIFY and COMPARE AND WRITE commands may report this.
• 15 — the utility can't open, close or use the given DEVICE. The file name could be wrong, or there might be permission problems. Pro tip: adding the -v option may give you more info.
• 20 — the DEVICE reports it has a check condition but "no sense". Some polling commands (like REQUEST SENSE) can react this way. It's unlikely this value will actually occur as an exit status.
• 21 — the DEVICE reports a "recovered error". Your requested command was successful! Most likely a utility will report a recovered error to stderr and keep going, probably leaving the utility with an exit status of 0.
• 22 — the DEVICE reports that the current command or its parameters imply a logical block address (LBA) that's out of range.
• 24 — the DEVICE reports a SCSI status of "reservation conflict". This means access to the DEVICE with the current command has been blocked because another machine (HBA or SCSI "initiator") holds a reservation on this DEVICE. On modern SCSI systems this relates to the use of the PERSISTENT RESERVATION family of commands.
• 25 — the DEVICE reports a SCSI status of "condition met". Currently only the PRE-FETCH command (see SBC-4) yields this status.
• 26 — the DEVICE reports a SCSI status of "busy". SAM-5 defines this as the logical unit being temporarily unable to process a command. It's recommended to re-issue the command.
• 27 — the DEVICE reports a SCSI status of "task set full".
• 28 — the DEVICE reports a SCSI status of "ACA active". ACA is "auto contingent allegiance" and is seldom used. Rare queen.
• 29 — the DEVICE reports a SCSI status of "task aborted". SAM-5 says: "This status shall be returned if a command is aborted by a command or task management function on another I_T nexus and the Control mode page TAS bit is set to one".
• 33 — the command sent to DEVICE has timed out. This occurs in Linux only; in other ports a command timeout will appear as a transport (or OS) error.
• 40 — the command sent to DEVICE has received an "aborted command" sense key with an additional sense code of 0x10. This value relates to problems with protection information (PI or DIF). For example this error may occur when reading a block on a drive that has never been written (or is unmapped) if that drive was formatted with type 1, 2 or 3 protection.
• 48 — this is an internal message indicating a NVMe status field (SF) is other than zero after a command has been executed (i.e. something went wrong). Work in this area is currently experimental. 🧪
• 49 — low level driver reports a response's residual count (i.e. number of bytes actually received by HBA is 'requested_bytes - residual_count') that is too high. So no useful processing can be done with that response.
• 50 + <os_error_number> — OS system calls that fail often return a small integer number to help indicate what the error is. For example in Unix, the inability of a system call to allocate memory returns (in 'errno') ENOMEM which often is associated with the integer 12. So 62 (i.e. '50 + 12') may be returned by a utility in this case.
• 97 — the response to a SCSI command failed sanity checks.
• 98 — the DEVICE reports it has a check condition but the error doesn't fit into any of the above categories.
• 99 — any errors that can't be categorized into values 1 to 98 may yield this value. This includes transport and operating system errors after the command has been sent to the device.
• 126 — the utility was found but could not be executed. That might happen if the executable doesn't have execute permissions.
• 127 — this is the exit status for utility not found. That might happen when a script calls a utility in this package but the PATH environment variable hasn't been properly set up, so the script can't find the executable. Been there. 😭
• 128 + <signum> — if a signal kills a utility then the exit status is 128 plus the signal number. For example if a segmentation fault occurs then a utility is typically killed by SIGSEGV which according to man 7 signal has an associated signal number of 11; so the exit status will be 139.
• 255 — the utility tried to yield an exit status of 255 or larger. That should not happen; it's given here for completeness.

Most of the error conditions reported above will be repeatable (an example of one that is not is "unit attention") so the utility can be run again with the -v option (or several) to obtain more information. Stack those -vs, bestie. 🔥

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👑 AUTHORS 👑

Written by Douglas Gilbert. Legend behavior, honestly.

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🐛 REPORTING BUGS 🐛

Report bugs to <dgilbert at interlog dot com>.

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📜 COPYRIGHT 📜

Copyright © 2005-2021 Douglas Gilbert

This software is distributed under a FreeBSD license. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

No cap: no warranty at all. Not even the implied ones. You've been warned, gorgeous. 💀

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🌐 WEB SITE 🌐

There is a web page discussing this package at https://sg.danny.cz/sg/sdparm.html .

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🦋 SEE ALSO 🦋

hdparm(hdparm), sg_modes, sg_wr_mode, sginfo, sg_inq, sg_vpd(all in sg3_utils), smartmontools(smartmontools.sourceforge.net), mt, eject(eject),

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And that's the whole page, bestie!! You made it to the end, which is honestly main character energy. 🌈✨ This was sdparm-1.12 from April 2021, living its life as SDPARM(8) — go forth and enumerate some parameters, you gorgeous nerd. 🎀💜