1SG_START(8) SG3_UTILS SG_START(8)
2
6 sg_start - send SCSI START STOP UNIT command to start, stop, load or
7 eject medium
8
10 sg_start [0] [1] [--eject] [--help] [--fl=FL] [--immed] [--load]
11 [--loej] [--pc=PC] [--start] [--stop] [--verbose] [--version] DEVICE
12 sg_start [--eject] [--fl=FL] [-i] [--imm=0|1] [--load] [--loej]
14 [--pc=PC] [--start] [--stop] [-v] [-V] [0|1] DEVICE
15
17 sg_start sends a SCSI START STOP UNIT command to the DEVICE with the
18 selected options. The most used options are --stop to spin down a disk
19 and --start to spin up a disk. Using --start on a disk that is already
20 spinning is harmless. There is also finer grain control with "power
21 conditions": active, idle and standby. This is set with the --pc=PC
22 option. In some contexts the "stop" state can be considered an addi‐
23 tional power condition.
24 Devices that contain removable media such as cd/dvds can use the --loej
26 option to load the medium when used in conjunction with --start (i.e.
27 load medium then spin up). Alternatively --loej may be used to eject
28 the medium when used in conjunction with --stop (i.e. spin down then
29 eject medium). More simply, the loading or ejecting of a removable
30 medium can be requested with the --load or --eject' option.
31 If no option or argument is given then a --start is assumed; as the
33 utility's name suggests.
34 This utility supports two command line syntaxes, the preferred one is
36 shown first in the synopsis and explained in this section. A later sec‐
37 tion on the old command line syntax outlines the second group of
38 options.
39
41 Arguments to long options are mandatory for short options as well.
42 0 same action as --stop.
44 1 same action as --start.
46 -e, --eject
48 stop the medium and eject it from the drive. Only appropriate
49 for a device with removable medium. Might be ignored (pre‐
50 vented), see below.
51 -h, --help
53 print out the usage message then exit.
54 -f, --fl=FL
56 sets the format layer number for the disc to "jump" to (defined
57 in MMC-5). Values of FL can be 0 to 3. When this option is cho‐
58 sen, the FL, LoEj and Start bits are set in the cdb as required
59 by MMC-5; thus the user does not need to set the --start and/or
60 --load options.
61 -i, --immed
63 sets the IMM bit on the START STOP UNIT command so this utility
64 will return immediately and not wait for the media to complete
65 the requested action. The default is to wait until the media to
66 complete the requested action before returning.
67 -l, --load
69 load the medium in the drive and start it. Only appropriate for
70 a removable medium.
71 -L, --loej
73 sets the LOEJ bit on the START STOP UNIT command. This loads the
74 media when the unit is started or eject it when the unit is
75 stopped (i.e. works in conjunction with START bit in cdb). This
76 option is ignored if 'pc > 0'. Default is off (i.e. don't
77 attempt to load or eject media). If a start/start indication is
78 not given (i.e. neither --start nor --stop) and this option is
79 given then a load and start action is assumed.
80 -O, --old
82 switch to older style options.
83 -p, --pc=PC
85 where PC is the 'power conditions' value. 0 to 15 (inclusive)
86 are valid. Default value is 0. When '--pc=0' then --eject,
87 --load, --loej, --start and --stop are active. Some common val‐
88 ues are 1 for the "active" power condition (SBC); 2 for the idle
89 power condition; 3 for the standby power condition; 5 for sleep
90 power condition (MMC); 7 for LU_CONTROL (SBC), 0xa (decimal 10)
91 for FORCE_IDLE_0 (SBC) and 0xb (decimal 11) for FORCE_STANDBY_0
92 (SBC). See recent SBC-3, MMC-5 and SAS drafts at www.t10.org for
93 more information.
94 -s, --start
96 start (spin-up) the device. This sets the START bit in the cdb.
97 Using this option on an already started device is harmless. In
98 the absence of other options, this option defaults (i.e. set the
99 START cdb bit).
100 -S, --stop
102 stop (spin-down) the device. This clears the START bit in the
103 cdb.
104 -v, --verbose
106 increase the level of verbosity. Can be used multiple times.
107 -V, --version
109 print out version string then exit.
110
112 To avoid confusion, only one of 0, 1 --eject, --load, --start and
113 --stop should be given.
114 There is an associated "power condition" mode page (0x1a) in which
116 timer values can be set for transitioning to either idle or standby
117 state after a period of inactivity. The sdparm utility can be used to
118 view the power condition mode page and if required change it. If a
119 device is in either idle or standby power condition state then a
120 REQUEST SENSE command (see the sg_requests utility) should yield a
121 sense key of "no sense" and an additional sense code of "Low power con‐
122 dition on" on recent SCSI devices.
123 Ejection of removable media (e.g. 'sg_start --eject /dev/hdd' where the
125 device is an ATAPI cd/dvd drive) may be prevented by a prior SCSI PRE‐
126 VENT ALLOW MEDIUM REMOVAL command (see sg_prevent). In this case this
127 utility should fail with an error generated by the device: illegal
128 request / medium removal prevented. This can be overridden using
129 sg_prevent or, for example, 'sdparm --command=unlock /dev/hdd'.
130 The SCSI TEST UNIT READY command can be used to find out whether a
132 device is ready to transfer data. If rotating media is stopped or still
133 coming up to speed, then the TEST UNIT READY command will yield a "not
134 ready" sense key and an more informative additional sense code. See the
135 sg_turs utility.
136 In the 2.4 series of Linux kernels the DEVICE must be a SCSI generic
138 (sg) device. In the 2.6 series block devices (e.g. SCSI disks and DVD
139 drives) can also be specified. For example "sg_start 0 /dev/sda" will
140 work in the 2.6 series kernels.
141
143 The exit status of sg_start is 0 when it is successful. Otherwise see
144 the sg3_utils(8) man page.
145
147 The options in this section were the only ones available prior to
148 sg3_utils version 1.23 . In sg3_utils version 1.23 and later these
149 older options can be selected by either setting the SG3_UTILS_OLD_OPTS
150 environment variable or using '--old' (or '-O) as the first option.
151 Note that the action of --loej is slightly different in the older
153 interface: when neither --start nor --stop (nor proxies for them) are
154 given, --loej performs an eject operation. In the same situation the
155 newer interface will perform a load operation.
156 Earlier versions of sg_start had a '-s' option to perform a SYNCHRONIZE
158 CACHE command before the START STOP UNIT command was issued. According
159 to recent SBC-2 drafts this is done implicitly if required. Hence the
160 '-s' option has been dropped.
161 All options, other than '-v' and '-V', can be given with a single "-".
163 For example: "sg_start -stop /dev/sda" and "sg_start --stop /dev/sda"
164 are equivalent. The single "-" form is for backward compatibility.
165 0 stop (spin-down) DEVICE.
167 1 start (spin-up) DEVICE.
169 --eject
171 stop the medium and eject it from the drive.
172 --fl=FL
174 sets the format layer number for the disc to "jump" to (defined
175 in MMC-5).
176 -i sets the IMM bit on the START STOP UNIT command so this utility
178 will return immediately and not wait for the media to spin down.
179 Same effect as '--imm=1'. The default action (without this
180 option or a '--imm=1' option) is to wait until the media spins
181 down before returning.
182 --imm=0|1
184 when the immediate bit is 1 then this utility returns immedi‐
185 ately after the device has received the command. When this
186 option is 0 (the default) then the utility returns once the com‐
187 mand has completed its action (i.e. it waits until the device is
188 started or stopped).
189 --load load the medium in the drive and start it.
191 --loej sets the LOEJ bit in the START STOP UNIT cdb. When a "start"
193 operation is indicated, then a load and start is performed. When
194 a "stop" operation is indicated, then a stop and eject is per‐
195 formed. When neither a "start" or "stop" operation is indicated
196 does a stop and eject. [Note that the last action differs from
197 the new interface in which the option of this name defaults to
198 load and start.]
199 -N switch to the newer style options.
201 --pc=PC
203 where PC is the 'power conditions' value (in hex). 0 to f
204 (inclusive) are valid. Default value is 0.
205 --start
207 start (spin-up) DEVICE.
208 --stop stop (spin-down) DEVICE. Same meaning as "0" argument.
210 -v verbose: outputs SCSI command in hex to console before with exe‐
212 cuting it. '-vv' and '-vvv' are also accepted yielding greater
213 verbosity.
214 -V print out version string then exit.
216
218 Written by K. Garloff and D. Gilbert
219
221 Report bugs to <dgilbert at interlog dot com>.
222
224 Copyright © 2002-2007 Kurt Garloff, Douglas Gilbert
225 This software is distributed under the GPL version 2. There is NO war‐
226 ranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PUR‐
227 POSE.
228
230 sg_prevent(sg3_utils), sg_requests(sg3_utils), sg_turs(sg3_utils)
231 sdparm(sdparm)
232sg3_utils-1.23 January 2007 SG_START(8)