1cpr(7) Device and Network Interfaces cpr(7)
2
6 cpr - Suspend and resume module
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9 /platform/'uname -m'/kernel/misc/cpr
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13 The cpr module is a loadable module used to suspend and resume the
14 entire system. You may wish to suspend a system to save power or to
15 power off temporarily for transport. The cpr module should not be used
16 in place of a normal shutdown when performing any hardware reconfigura‐
17 tion or replacement. In order for the resume operation to succeed, it
18 is important that the hardware configuration remain the same. When the
19 system is suspended, the entire system state is preserved in non-
20 volatile storage until a resume operation is conducted.
21 dtpower(1M) or power.conf(4) are used to configure the suspend-resume
24 feature.
25 The speed of suspend and resume operations can range from 15 seconds
28 to several minutes, depending on the system speed, memory size, and
29 load.
30 During resume operation, the SIGTHAW signal is sent to all processes to
33 allow them to do any special processing in response to suspend-resume
34 operation. Normally applications are not required to do any special
35 processing because of suspend-resume, but some specialized processes
36 can use SIGTHAW to restore the state prior to suspend. For example, X
37 can refresh the screen in response to SIGTHAW.
38 In some cases the cpr module may be unable to perform the suspend oper‐
41 ation. If a system contains additional devices outside the standard
42 shipped configuration, it is possible that device drivers for these
43 additional devices might not support suspend-resume operations. In
44 this case, the suspend fails and an error message is displayed. These
45 devices must be removed or their device drivers unloaded for the sus‐
46 pend operation to succeed. Contact the device manufacturer to obtain a
47 new version of device driver that supports suspend-resume.
48 A suspend may also fail when devices or processes are performing
51 critical or time-sensitive operations (such as realtime operations).
52 The system will remain in its current running state. Messages reporting
53 the failure will be displayed on the console and status returned to the
54 caller. Once the system is successfully suspended the resume operation
55 will succeed, barring external influences such as a hardware reconfigu‐
56 ration.
57 Some network-based applications may fail across a suspend and resume
60 cycle. This largely depends on the underlying network protocol and the
61 applications involved. In general, applications that retry and auto‐
62 matically reestablish connections will continue to operate transpar‐
63 ently on a resume operation; those applications that do not will
64 likely fail.
65
67 See attributes(5) for descriptions of the following attributes:
68 ┌─────────────────────────────┬─────────────────────────────┐
73 │ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
74 ├─────────────────────────────┼─────────────────────────────┤
75 │Availability │SUNWcpr │
76 ├─────────────────────────────┼─────────────────────────────┤
77 │Interface stability │Unstable │
78 └─────────────────────────────┴─────────────────────────────┘
79
81 dtpower(1M) (OpenWindows Reference Manual), pmconfig(1M), uadmin(1M),
82 uadmin(2), power.conf(4), attributes(5)
83 Using Power Management
86 Writing Device Drivers
89
91 Certain device operations such as tape and floppy disk activities are
92 not resumable due to the nature of removable media. These activities
93 are detected at suspend time, and must be stopped before the suspend
94 operation will complete successfully.
95 Suspend-resume is currently supported only on a limited set of hard‐
98 ware platforms. Please see the book Using Power Management for a com‐
99 plete list of platforms that support system Power Management. See
100 uname(2) to programatically determine if the machine supports suspend-
101 resume.
102SunOS 5.11 7 May 2001 cpr(7)