1SDPARM(8) SDPARM SDPARM(8)
2
6 sdparm - access SCSI modes pages; read VPD pages; send simple SCSI com‐
7 mands.
8
10 sdparm [--all] [--clear=STR] [--command=CMD] [--dbd] [--defaults]
11 [--dummy] [--flexible] [--get=STR] [--help] [--hex] [--inquiry]
12 [--long] [--num-desc] [--page=PG[,SPG]] [--quiet] [--readonly] [--save]
13 [--set=STR] [--six] [--transport=TN] [--vendor=VN] [--verbose] [--ver‐
14 sion] DEVICE [DEVICE...]
15 sdparm --enumerate [--all] [--inquiry] [--long] [--page=PG[,SPG]]
17 [--transport=TN] [--vendor=VN]
18 sdparm --wscan [--verbose]
20
22 This utility fetches and potentially changes SCSI device (e.g. disk)
23 mode pages. Inquiry data including Vital Product Data (VPD) pages can
24 also be displayed. Commands associated with starting and stopping the
25 medium; loading and unloading the medium; and other housekeeping func‐
26 tion may also be issued by this utility.
27 Of the three invocations shown in the synopsis, the first is the most
29 general. The second variant that uses --enumerate is for dumping infor‐
30 mation held in sdparm's internal tables. The last variant is for Win‐
31 dows only and lists the available device names; see the OPTIONS entry
32 for --wscan.
33 If no options (other than DEVICE) are given then a selection of common
35 mode page fields for that device are listed. If the --long option is
36 also given then a description of the fields is placed on the right of
37 each line. If the --all option is given then all known mode page fields
38 for that device are listed. Individual fields can be displayed with the
39 --get=STR option (e.g. '--get=WCE' to fetch the state of the Writeback
40 Cache Enable field).
41 This utility completes with an exit status of 0 when successful. For
43 other values see the EXIT STATUS section below.
44 One or more DEVICE arguments can be given. The utility will essentially
46 apply the given options to each DEVICE in the list. If an error is
47 detected, it is noted and the utility continues. Error value 5 (file
48 open or close problem) is treated as lower priority when other errors
49 are detected. The exit status is the most recently detected error value
50 (excluding error value 5 if other errors have been detected). If all
51 actions succeed the exit status is zero.
52 By default this utility shows mode pages that are common to all trans‐
54 port protocols. These are termed as "generic" mode pages. If there is
55 no match on a generic mode page name or field then those pages specific
56 to the SAS transport are checked. Transport protocol specific mode
57 pages are selected with the --transport=TN option. See the TRANSPORT
58 section below. Vendor specific mode pages are selected with the --ven‐
59 dor=VN option. See the VENDORS section below.
60 Although originally for SCSI disks (or storage devices that appear to
62 the OS as SCSI disks) many of the mode pages are for other SCSI device
63 types. These include CD/DVD players that use the ATAPI (or any other)
64 transport, SCSI tapes drives and SCSI enclosures.
65 When the --inquiry option is given without a page number then the
67 Device Identification VPD page (page number 0x83) is requested and if
68 found it is decoded and output. If no page number is given and the
69 --all option is given then a list of VPD page names (but not their con‐
70 tents) supported by the DEVICE is output. When both the --inquiry and
71 --page=PG options are given then the VPD page can be specified as an
72 abbreviation (e.g. "sp" for the SCSI ports VPD page) or numerically
73 (e.g. "0x88"). If a VPD page is returned by the DEVICE but sdparm can‐
74 not decode it or the --hex option is given then it is output in hex.
75
77 Mandatory arguments to long options are mandatory for short options as
78 well. If an option takes a numeric argument then that argument is
79 assumed to be decimal unless otherwise indicated (e.g. with a leading
80 "0x" or a trailing "h"). The options are in alphabetical order, based
81 on the long option name.
82 -a, --all
84 output all recognized fields for the device type (e.g. disk) of
85 the DEVICE. Without this option (or the --page=PG[,SPG] option)
86 the default action is to output a relatively small number of
87 commonly used fields from different pages. When a specific
88 (mode) page number is given with the --page=PG[,SPG] option then
89 all the fields of that page are output (irrespective of the set‐
90 ting of this option). For this option's action when used with
91 the --enumerate option see the ENUMERATE section below.
92 -c, --clear=STR
94 In its simplest form STR contains a field acronym_name or a
95 field numerical descriptor. In the absence of an explicit value
96 argument (e.g. '--clear=WCE=1'), the field has its value cleared
97 to zero. See the PARAMETERS section below.
98 -C, --command=CMD
100 Perform given CMD. See section below on COMMANDS. To enumerate
101 supported commands use '-e -C x' (using any CMD name, valid or
102 otherwise).
103 -B, --dbd
105 disable block descriptors. This is a bit in MODE SENSE cdbs that
106 rarely needs to be set. One known case is a MODE SENSE 6 issued
107 to a Reduced Block Commands (RBC) device where the RBC standard
108 says it shall be set.
109 -D, --defaults
111 sets the given mode page to its default values. Requires the
112 --page=PG[,SPG] option to be given to specify the mode page. To
113 make the default mode page values also the saved mode page val‐
114 ues, use the --save option as well.
115 -d, --dummy
117 when set inhibits changes being placed in the DEVICE's mode
118 page. Instead the mode data that would have been sent to a MODE
119 SELECT command, is output in ASCII hex to the console. This
120 option is mainly for testing.
121 -e, --enumerate
123 lists out descriptive information about the pages and fields
124 known to this utility. Ignores the DEVICE argument and other
125 options apart from the --all, --inquiry, --long,
126 --page=PG[,SPG], --transport=TN and --vendor=VN. If --enumerate
127 is given without other options then the known (generic) mode
128 pages are listed. See the ENUMERATE section below.
129 -f, --flexible
131 Some devices, bridges and/or drivers attempt crude transforma‐
132 tions between mode sense 6 and 10 byte commands without cor‐
133 rectly rebuilding the response. This will cause the response to
134 be mis-interpreted (usually with an error saying the response is
135 malformed). With this option, the length of the response is
136 checked, and if it looks wrong, various corrections are
137 attempted. This option will also allow mode pages that don't
138 belong to the current device's peripheral type to be listed.
139 -g, --get=STR
141 In its simplest form STR contains a field acronym_name or a
142 field numerical descriptor. The field is fetched from mode page.
143 See the PARAMETERS section below. The --long and --hex options
144 effect the output format. Also if a value of "1" is given (e.g.
145 '--get=WCE=1') only the current value is output (i.e. not the
146 change mask, the default value and the saved value).
147 -h, --help
149 output the usage message then exit.
150 -H, --hex
152 rather than trying to decode mode (or VPD) pages, print them out
153 in hex. When used with the --get=STR option the corresponding
154 current, changeable, default and saved values are output in hex,
155 prefixed by "0x" and space separated. If a value of "1" is given
156 with the --get=STR option (e.g. '--get=WCE=1') then only the
157 current value is output in hex, prefixed by "0x". If a value of
158 "2" is given with the --get=STR option then only the current
159 value is output as a (signed) integer. This option can be used
160 multiple times (e.g. '-HH'). Useful with the ATA Information VPD
161 page which usually outputs its IDENTIFY (PACKET) DEVICE response
162 in 16 bit hex words; with '-HH' outputs that response in hex
163 bytes; with '-HHH' outputs the same response in a format suit‐
164 able for 'hdparm --Istdin' to decode.
165 -i, --inquiry
167 output INQUIRY VPD pages. In the absence of this option the
168 default action is to output mode pages. If the --inquiry option
169 is given without the --page=PG[,SPG] option then the device
170 identification VPD page (0x83) is decoded and output. If this
171 option and the --all option are given then the supported VPD
172 pages page (0x0) is decoded and output.
173 -l, --long
175 output extra information. In the case of mode page fields a
176 description (with units if applicable) is output to the right.
177 If used twice, then for some fields more information about its
178 values is given on one or more following lines, each prefixed by
179 a tab character. For usage with --enumerate see the ENUMERATE
180 section below.
181 -n, --num-desc
183 for a mode page that can have descriptors, the number of
184 descriptors for the given page on the DEVICE is output. Other‐
185 wise 0 is output.
186 -p, --page=PG[,SPG]
188 supply the page number (PG) and optionally the sub page number
189 (SPG) of the mode (or VPD) page to fetch. These numbers are
190 interpreted as decimal unless prefixed with "0x" or a trailing.
191 Sub page numbers are only valid for mode pages (not VPD pages).
192 Alternatively an abbreviation for a page can be given (see next
193 entry).
194 -p, --page=STR
196 a two or three letter abbreviation for a page can be given.
197 Known mode page abbreviations are checked first followed by
198 known VPD page abbreviations. For example '--page=ca' matches
199 the caching mode page. If no match is found then an error is
200 issued and a list of possibilities in the current context is
201 given (so '-p x' can be quite useful). If the STR matches a
202 known VPD page abbreviation then the --inquiry option is
203 assumed. For usage with --enumerate see the ENUMERATE section
204 below.
205 -q, --quiet
207 suppress output of device name followed by the vendor, product
208 and revision strings fetched from an INQUIRY response. Without
209 this option such a line is typically the first line output by
210 sdparm. Reduces output from the device identification VPD page,
211 typically to one line (or none) for each of di_lu, di_port,
212 di_target and di_asis.
213 -r, --readonly
215 override other logic to open DEVICE in read-only mode. This
216 option may be useful if a command is being sent to an ATA disk
217 via a SCSI command set. For example in Linux '-C stop' may
218 require this option to stop an ATA disk being restarted immedi‐
219 ately.
220 -S, --save
222 when a mode page is being modified (by using the --clear=STR
223 and/or --set=STR options) then the default action is to modify
224 only the current values mode page. When this option is given
225 then the corresponding value(s) in the saved values mode page is
226 also changed. The next time the device is power cycled (or
227 reset) the saved values mode page becomes (i.e. is copied to)
228 the current values mode page. See NOTES section below.
229 -s, --set=STR
231 in its simplest form STR contains a field acronym_name or a
232 field numerical descriptor. In the absence of an explicit value,
233 each acronym_name has its value set to (all) ones. This means a
234 16 bit field will be set to 0xffff which is 65535 in decimal.
235 Alternatively each acronym_name or numerical descriptor may be
236 followed by "=<n>" where <n> is the value to set that field to.
237 See the PARAMETERS section below.
238 -6, --six
240 The default action of this utility is to issue MODE SENSE and
241 MODE SELECT SCSI commands with 10 byte cdbs. When this option is
242 given the 6 byte cdb variants are used. RBC and old SCSI devices
243 may need this option. This utility outputs a suggestion to use
244 this option if the SCSI status indicates that the 10 byte cdb
245 variant is not supported.
246 -t, --transport=TN
248 Specifies the transport protocol where TN is either a number in
249 the range 0 to 15 (inclusive) or an abbreviation (e.g. "fcp" for
250 the Fibre Channel Protocol). One way to list available transport
251 protocols numbers and their associated abbreviations is to give
252 an invalid transport protocol number such as '-t x'; another way
253 is '-e -l'.
254 -M, --vendor=VN
256 Specifies the vendor (i.e. manufacturer) where VN is either a
257 number (0 or more) or an abbreviation (e.g. "sea" for Seagate
258 disk vendor specific). One way to list available vendor numbers
259 and their associated abbreviations is to give an invalid vendor
260 number such as '-M x'; another way is '-e -l'.
261 -v, --verbose
263 increase the level of verbosity, (i.e. debug output). In some
264 cases more decoding is done (e.g. fields within a standard
265 INQUIRY response).
266 -V, --version
268 print the version string and then exit.
269 -w, --wscan
271 this option is available in Windows only. It lists storage
272 device names and the corresponding volumes, if any. When used
273 twice it adds the "bus type" of the closest transport (e.g. a
274 SATA disk in a USB connected enclosure has bus type Usb). When
275 used three times a SCSI adapter scan is added. When used four
276 times only a SCSI adapter scan is shown. See examples below and
277 the "Win32 port" section in the README file.
278
280 A mode page for which no abbreviation is known (e.g. a vendor specific
281 mode page) can be listed in hexadecimal by using the option combination
282 '--page=PG --hex'.
283 Numbers input to sdparm (e.g. in the command line arguments) are
285 assumed to be in decimal unless there is a hexadecimal indicator. A
286 hexadecimal indicator is either a leading '0x' or '0X' (i.e. the C lan‐
287 guage convention) or a trailing 'h' or 'H' (i.e. the convention used at
288 www.t10.org ). In the case of --page= either a string or number is
289 expected, so hex numbers like 'ch' (12) should be prefixed by a zero
290 (e.g. '0ch').
291 The SPC-4 draft (rev 2) says that devices that implement no distinction
293 between current and saved pages can return an error (ILLEGAL REQUEST,
294 invalid field in cdb) if the SP bit (which corresponds to the --save
295 option) is _not_ set. In such cases the --save option needs to be
296 given.
297 If the --save option is given but the existing mode page indicates (via
299 its PS bit) that the page is not savable, then this utility generates
300 an error message. That message suggests to try again without the --save
301 option.
302 Since the device identification VPD page (acronym_name "di") poten‐
304 tially contains a lot of diverse designators, several associated
305 acronyms are available. They are "di_lu" for designators associated
306 with the addressed logical unit, "di_port" for designators associated
307 with the target port (which the command arrived via) and "di_target"
308 for designators associated with the target device. When "di" is used
309 designators are grouped by lu, then port and then target device. To
310 see all designators decoded in the order that they appear in the VPD
311 page use "di_asis".
312 In the linux kernel 2.6 series any device node that understands a SCSI
314 command set (e.g. SCSI disks and CD/DVD drives) may be specified. More
315 precisely the driver that "owns" the device node must support the SG_IO
316 ioctl. In the lk 2.4 series only SCSI generic (sg) device nodes support
317 the SG_IO ioctl. However in the lk 2.4 series other SCSI device nodes
318 are mapped within this utility to their corresponding sg device nodes.
319 So if there is a SCSI disk at /dev/sda then 'sdparm /dev/sda' will work
320 in both the lk 2.6 and lk 2.4 series. However if there is an ATAPI
321 cd/dvd drive at /dev/hdc then 'sdparm /dev/hdc' will only work in the
322 lk 2.6 series.
323 In the Linux 2.6 series, especially with ATA disks, using sdparm to
325 stop (spin down) a disk may not be sufficient and other mechanisms will
326 start the disk again some time later. The user might additionally mark
327 the disk as "offline" with 'echo offline > /sys/block/sda/device/state'
328 where sda is the block name of the disk. To restart the disk "offline"
329 can be replaced with "running".
330
332 In their simplest form the --clear=, --get= and --set= options (or
333 their short forms) take an acronym_name such as "WCE". In the case of
334 '--get=WCE' the value of "Writeback Cache Enable" in the caching mode
335 page will be fetched. In the case of '--set=WCE' that bit will be set
336 (to one). In the case of '--clear=WCE' that bit will be cleared (to
337 zero). When an acronym_name is given then the mode page is imputed from
338 that acronym_name (e.g. WCE is in the caching mode page).
339 Instead of an acronym_name a field within a mode page can be described
341 numerically with a <start_byte>:<start_bit>:<num_bits> tuple. These are
342 the <start_byte> (origin 0) within the mode page, a <start_bit> (0 to 7
343 inclusive) and <num_bits> (1 to 64 inclusive). For example, the low
344 level representation of the RCD bit (the "Read Cache Disable bit in the
345 caching mode page) is "2:0:1". The <start_byte> can optionally be given
346 in hex (e.g. '--set=0x2:0:1' or '--set=2h:0:1'). With this form the
347 --page= option is required to establish which mode page is to be used.
348 Either form can optionally be followed by "=<val>". By default <val> is
350 decimal but can be given in hex in the normal fashion. Here are some
351 examples: '--set=2h:0:1=1h' and '-s MRIE=0x3'. When the acronym_name or
352 numeric form following --clear= is not given an explicit '=<val>' then
353 the value defaults to zero. When the acronym_name or numeric form fol‐
354 lowing --set= is not given an explicit '=<val>' then the value defaults
355 to "all ones" (i.e. as many as <num_bits> permits). For example
356 '--clear=WCE' and '--clear=WCE=0' have the same meaning: clear Write‐
357 back Cache Enable or, put more simply: turn off the writeback cache.
358 Multiple fields within the same mode page can be changed by giving a
360 comma separated list of acronym_names and/or the numerical form. For
361 example: '--set=TEST,MRIE=6'.
362 Some mode page have multiple descriptors. They typically have a fixed
364 header section at the start of the mode page that includes a field con‐
365 taining the number of descriptors that follow. Following the header is
366 a variable number of descriptors. An example is the SAS Phy Control and
367 Discover mode page. An acronym_name may include a trailing '.<num>'
368 where "<num>" is a descriptor number (origin 0). For example '-t sas -g
369 PHID.0' and '-t sas -g PHID' will yield the phy identifier of the first
370 descriptor of the above mode page; '-t sas -g PHID.1' will yield the
371 phy identifier of the second descriptor.
372
374 The --enumerate option essentially dumps out static information held by
375 this utility. A list of --enumerate variants and their actions follows.
376 For brevity subsequent examples of options are shown in their shorter
377 form.
378 --enumerate list generic mode page information
380 -e --all list generic mode page contents
381 (i.e. parameters)
382 -e --page=rw list contents of read write error
383 recovery mode page
384 -e --inquiry list VPD pages this utility can decode
385 -e --long list generic mode pages, transport
386 protocols, mode pages for each
387 supported transport protocol and
388 supported commands
389 -e -l --all additionally list the contents of
390 each mode page
391 -e --transport=fcp list mode pages for the fcp
392 transport protocol
393 -e -t fcp --all additionally list the contents of
394 each mode page
395 -e --vendor=sea list vendor specific mode pages for
396 "sea" (Seagate)
397 -e -M sea --all additionally list the contents of vendor
398 specific mode pages for "sea" (Seagate)
399 -e -p pcd -l list contents of SAS phy control and
400 discovery mode page plus (due to "-l")
401 some descfriptor format information
402 When known mode pages are listed (via the --enumerate option) each
404 line starts with a two or three letter abbreviation. This is followed
405 by the page number (in hex prefixed by "0x") optionally followed by a
406 comma and the subpage number. Finally the descriptive name of the mode
407 page (e.g. as found in SPC-4) is output.
408 When known parameters (fields) of a mode page are listed, each line
410 starts with an acronym (indented a few spaces). This will match (or be
411 an acronym for) the description for that field found in the (draft)
412 standards. Next are three numbers, separated by colons, surrounded by
413 brackets. These are the start byte (in hex, prefixed by "0x") of the
414 beginning of the field within the mode page; the starting bit (0
415 through 7 inclusive) and then the number of bits. The descriptive name
416 of the parameter (field) is then given. If appropriate the descriptive
417 name includes units (e.g. "(ms)" means the units are milliseconds).
418 Adding the '-ll' option will list information about possible field val‐
419 ues for selected mode page parameters.
420 Mode parameters for which the num_bits is greater than 1 can be viewed
422 as unsigned integers. Often 16 and 32 bit fields are set to 0xffff and
423 0xffffffff respectively (all ones) which usually has a special meaning
424 (see drafts). This utility outputs such values as "-1" to save space
425 (rather than their unsigned integer equivalents). "-1" can also be
426 given as the value to a mode page field acronym (e.g. '--set=INTT=-1'
427 sets the interval timer field in the Informational Exceptions control
428 mode page to 0xffffffff).
429
431 SCSI transport protocols are a relatively specialized area that can be
432 safely ignored by the majority of users.
433 Some transport protocols have protocol specific mode pages. These are
435 usually the disconnect-reconnect (0x2), the protocol specific logical
436 unit (0x18) and the protocol specific port (0x19) mode pages. In some
437 cases the latter mode page has several subpages. The most common trans‐
438 port protocol abbreviations likely to be used are "fcp", "spi" and
439 "sas".
440 Many of the field names are re-used in the same position so the acro‐
442 nym_name namespaces have been divided between generic mode pages (i.e.
443 when the --transport= option is _not_ given) and a namespace for each
444 transport protocol. A LUPID field from the protocol specific logical
445 unit (0x18) mode page and the PPID field from protocol specific port
446 (0x19) mode page are included in the generic modes pages; this is so
447 the respective (transport) protocol identifiers can be seen. In most
448 cases the user will know what the "port" transport is (i.e. the same
449 transport as the HBA in the computer) but the logical unit's transport
450 could be different.
451
453 SCSI leaves a lot of space for vendor specific information. Often this
454 is described in product manuals. The --vendor=VN (or -M=VN) option
455 allows known vendor specific mode pages to be examined and/or modified
456 by acronym.
457 In this utility the syntax and semantics of vendor specific mode pages
459 is very similar to those of transport protocol specific mode pages.
460 Both cannot be specified together. Vendor specific modes pages can
461 still be accessed numerically (as shown at the end of the EXAMPLES sec‐
462 tion).
463
465 The command option sends a SCSI command to the DEVICE. If the command
466 fails then this is reflected in the non-zero exit status. To obtain
467 more information about the error use the -v option.
468 capacity
470 sends a READ CAPACITY command (valid for disks and cd/dvd
471 media). If successful yields "blocks: " [the number of blocks],
472 "block_length: " [typically either 512 or 2048] and "capac‐
473 ity_mib: " [capacity in MibiBytes (1048576 byte units)].
474 eject stops the medium and ejects it from the device. Note that ejec‐
476 tion (by command or button) may be prevented in which case the
477 'unlock' command may be useful in extreme cases. Typically only
478 appropriate for cd/dvd drives and disk drives with removable
479 media. Objects if sent to another peripheral device type (but
480 objection can be overridden with '-f' option).
481 load loads the medium and and starts it (i.e. spins it up). See
483 'eject' command for supported device types.
484 profile
486 lists the various formats that a CD/DVD/HD-DVD/BD drive sup‐
487 ports. These are called "profiles" in the MMC standard. The pro‐
488 files are listed one per line. If media is in the drive then
489 the profile that matches the media (if any) has an "*" to the
490 right of the line.
491 ready sends the "Test Unit Ready" SCSI command to the DEVICE. No error
493 is reported if the device will respond to data requests (e.g.
494 READ) in a reasonable timescale. For example, if a disk is
495 stopped then it will report "not ready". All devices should
496 respond to this command.
497 sense sends a REQUEST SENSE command. It reports a hardware threshold
499 exceeded, warning or low power condition if flagged. If a
500 progress indication is present (e.g. during a format) then it
501 will be output as a percentage. Yields a process status of 0 if
502 the command succeeds and the sense key is 0; else yields 1. The
503 --quiet option can be used to lessen output, and --hex to output
504 sense data in hex.
505 speed=SPEED
507 permits the speed of a CD, DVD, HD_DVD or BD disc in a drive to
508 be set (or at least influenced). It has this format: --com‐
509 mand=speed=SPEED where SPEED is in kilobytes per second. In this
510 case a kilobyte is 1000 bytes. The "times one" speed for a CD is
511 176.4 kB/s, for a DVD is 1350 kB/s and for both HD-DVD and BD it
512 is 4500 kB/s. If SPEED is zero then the drive is set to the
513 speed that it considers gives optimal performance. This command
514 sends a SET STREAMING multi-media command (MMC) to the drive.
515 The EXACT bit is clear so the drive will round the given SPEED
516 as necessary. The command is designed to control read speed;
517 setting write speed should be left to "burning" programs.
518 start starts the medium (i.e. spins it up). Harmless if medium has
520 already been started. See 'eject' command for supported device
521 types. If the DEVICE is an ATA disk in Linux the '--readonly'
522 option may be required.
523 stop stops the medium (i.e. spins it down). Harmless if medium has
525 already been stopped. See 'eject' command for supported device
526 types. If the DEVICE is an ATA disk in Linux the '--readonly'
527 option may be required. See the NOTES section above.
528 sync sends a SYNCHRONIZE CACHE command. The device should flush any
530 data held in its (volatile) buffers to the media.
531 unlock tells a device to allow medium removal. It uses the SCSI "pre‐
533 vent allow medium removal" command. This is desperation stuff,
534 possibly overriding a prevention applied by the OS on a mounted
535 file system. The "eject" utility (from the "eject" package) is
536 more graceful and should be tried first. This command is only
537 appropriate for devices with removable media.
538 For loading and ejecting tapes the mt utility should be used (i.e. not
540 these commands). The 'ready' command is valid for tape devices.
541
543 To list the common (generic) mode parameters of a disk:
544 sdparm /dev/sda
546 To list the designators within the device identification VPD page of a
548 disk:
549 sdparm --inquiry /dev/sda
551 To see all parameters for the caching mode page:
553 sdparm --page=ca /dev/sda
555 To see all parameters for the caching mode page with parameter descrip‐
557 tions to the right:
558 sdparm --page=ca --long /dev/sda
560 To get the WCE values (current changeable default and saved) in hex:
562 sdparm -g WCE -H /dev/sda
564 0x01 0x00 0x01 0x01
565 To get the WCE current value in hex:
567 sdparm -g WCE=1 -H /dev/sda
569 0x01
570 To set the "Writeback Cache Enable" bit in the current values page:
572 sdparm --set=WCE /dev/sda
574 To set the "Writeback Cache Enable" bit in the current and saved values
576 page:
577 sdparm --set=WCE --save /dev/sda
579 To set the "Writeback Cache Enable" and clear "Read Cache Disable":
581 sdparm --set=WCE --clear=RCD --save /dev/sda
583 The previous example can also by written as:
585 sdparm -s WCE=1,RCD=0 -S /dev/sda
587 To re-establish the manufacturer's defaults in the current and saved
589 values of the caching mode page:
590 sdparm --page=ca --defaults --save /dev/sda
592 If an ATAPI cd/dvd drive is at /dev/hdc then its common (mode) parame‐
594 ters could be listed in the lk 2.6 series with:
595 sdparm /dev/hdc
597 If there is a DVD in the drive at /dev/hdc then it could be ejected in
599 the lk 2.6 series with:
600 sdparm --command=eject /dev/hdc
602 If the ejection is being prevented by software then that can be over‐
604 ridden with:
605 sdparm --command=unlock /dev/hdc
607 One disk vendor has a "Performance Mode" bit (PM) in the vendor spe‐
609 cific unit attention mode page [0x0,0x0]. PM=0 is server mode (the
610 default) while PM=1 is desktop mode. Desktop mode can be set (both cur‐
611 rent and saved values) with:
612 sdparm --page=0 --set=2:7:1=1 --save /dev/sda
614 The resultant change can be viewed in hex with the --hex option as
616 there are no acronyms for vendor extensions yet. The PM bit is now cov‐
617 ered by vendor specific mode pages and the above can also be accom‐
618 plished with:
619 sdparm --vendor=sea --set=PM --save /dev/sda
621 What follows are some examples from Windows using the '--wscan' option.
623 The idea is to list the storage device names on the system that might
624 be invoked by other uses of sdparm.
625 # sdparm --wscan
627 PD0 [C] FUJITSU MHY2160BH 0000
628 PD1 [DF] WD 2500BEV External 1.05 WD-WXE90
629 CDROM0 [E] MATSHITA DVD/CDRW UJDA775 CB03
630 So 'sdparm -a CDROM0' and 'sdparm -a E' will show all the (known) mode
632 page fields for the Matshita DVD/CD drive. By using the '--wsacan'
633 option twice, the bus type (as seen by the OS) is added to the output:
634 # sdparm -ww
636 PD0 [C] <Ata > FUJITSU MHY2160BH 0000
637 PD1 [DF] <Usb > WD 2500BEV External 1.05 WD-WXE90
638 CDROM0 [E] <Atapi> MATSHITA DVD/CDRW UJDA775 CB03
639 And the pattern continues to add a SCSI adapter scan. This may be use‐
641 ful if there are specialized storage related devices (e.g. a SES device
642 in an enclosure) but does add much extra information in this case.
643 # sdparm -www
645 PD0 [C] <Ata > FUJITSU MHY2160BH 0000
646 PD1 [DF] <Usb > WD 2500BEV External 1.05 WD-WXE90
647 CDROM0 [E] <Atapi> MATSHITA DVD/CDRW UJDA775 CB03
648 SCSI0:0,0,0 claimed=1 pdt=0h FUJITSU MHY2160BH 0000
650 SCSI1:0,0,0 claimed=1 pdt=5h MATSHITA DVD/CDRW UJDA775 CB03
651
653 To aid scripts that call sdparm, the exit status is set to indicate
654 success (0) or failure (1 or more). Note that some of the lower values
655 correspond to the SCSI sense key values. The exit status values are:
656 0 success
658 1 syntax error. Either illegal command line options, options with
660 bad arguments or a combination of options that is not permitted.
661 2 the DEVICE reports that it is not ready for the operation
663 requested. The device may be in the process of becoming ready
664 (e.g. spinning up but not at speed) so the utility may work
665 after a wait.
666 3 the DEVICE reports a medium or hardware error (or a blank
668 check). For example an attempt to read a corrupted block on a
669 disk will yield this value.
670 5 the DEVICE reports an "illegal request" with an additional sense
672 code other than "invalid operation code". This is often a sup‐
673 ported command with a field set requesting an unsupported capa‐
674 bility. For commands that require a "service action" field this
675 value can indicate that the command is not supported.
676 6 the DEVICE reports a "unit attention" condition. This usually
678 indicates that something unrelated to the requested command has
679 occurred (e.g. a device reset) potentially before the current
680 SCSI command was sent. The requested command has not been exe‐
681 cuted by the device. Note that unit attention conditions are
682 usually only reported once by a device.
683 9 the DEVICE reports an illegal request with an additional sense
685 code of "invalid operation code" which means that it doesn't
686 support the requested command.
687 11 the DEVICE reports an aborted command. In some cases aborted
689 commands can be retried immediately (e.g. if the transport
690 aborted the command due to congestion).
691 15 the utility is unable to open, close or use the given DEVICE.
693 The given file name could be incorrect or there may be permis‐
694 sion problems. Adding the -v option may give more information.
695 20 the DEVICE reports it has a check condition but "no sense".
697 Some polling commands (e.g. REQUEST SENSE) can react this way.
698 It is unlikely that this value will occur as an exit status.
699 21 the DEVICE reports a "recovered error". The requested command
701 was successful. Most likely a utility will report a recovered
702 error to stderr and continue, probably leaving the utility with
703 an exit status of 0 .
704 33 the command sent to DEVICE has timed out. This occurs in Linux
706 only; in other ports a command timeout will appear as a trans‐
707 port (or OS) error.
708 97 the response to a SCSI command failed sanity checks.
710 98 the DEVICE reports it has a check condition but the error
712 doesn't fit into any of the above categories.
713 99 any errors that can't be categorized into values 1 to 98 may
715 yield this value. This includes transport and operating system
716 errors after the command has been sent to the device.
717 Most of the error conditions reported above will be repeatable (an
719 example of one that is not is "unit attention") so the utility can be
720 run again with the -v option (or several) to obtain more information.
721
723 Written by Douglas Gilbert.
724
726 Report bugs to <dgilbert at interlog dot com>.
727
729 Copyright © 2005-2010 Douglas Gilbert
730 This software is distributed under a FreeBSD license. There is NO war‐
731 ranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PUR‐
732 POSE.
733
735 There is a web page discussing this package at
736 http://sg.danny.cz/sg/sdparm.html .
737
739 hdparm(hdparm), sg_modes, sg_wr_mode, sginfo, sg_inq, sg_vpd,
740 sg_scan(all in sg3_utils), smartmontools(smartmontools.source‐
741 forge.net), mt, eject(eject),
742sdparm-1.06 July 2010 SDPARM(8)