Documentation/power/swsusp.rst

32    power states like "standby", which normally don't turn USB off.)
36   line or specify it using /sys/power/resume.
41   in /sys/power/resume_offset.
45 	echo shutdown > /sys/power/disk; echo disk > /sys/power/state
47 - If you feel ACPI works pretty well on your system, you might try::
49 	echo platform > /sys/power/disk; echo disk > /sys/power/state
51 - If you would like to write hibernation image to swap and then suspend
54 	echo suspend > /sys/power/disk; echo disk > /sys/power/state
56 - If you have SATA disks, you'll need recent kernels with SATA suspend
58   are built into kernel -- not modules. [There's way to make
64 	echo N > /sys/power/image_size
68 - The resume process checks for the presence of the resume device,
72 - The resume process may be triggered in two ways:
79      the init script by using the /sys/power/resume file.  It is vital
81      read-only) otherwise data may be corrupted.
87 Last revised: 2003-10-20 by Pavel Machek
90 -------------------------
121   echo 3 > /proc/acpi/sleep       # for suspend to ram, but with more power
139   bringing machine down? Suspend to disk, rearrange power cables,
142   You have your server on UPS. Power died, and UPS is indicating 30
163     between 0-640KB. That way, I'd have to make sure that 0-640KB is free
167   data and disk caches into "used memory" by saving them in
174   Yes. That's what echo platform > /sys/power/disk does.
181   suspend-to-disk which is available as separate patches for 2.4 and 2.6
196   kernel threads are controlled during hibernation or system-wide suspend (on
197   some architectures).  See freezing-of-tasks.txt for details.
218   Do selective suspend during runtime power management, that's okay. But
219   it's useless for suspend-to-disk. (And I do not see how you could use
220   it for suspend-to-ram, I hope you do not want that).
262     cat /proc/[0-9]*/maps | grep / | sed 's:.* /:/:' | sort -u | while read file
264       test -f "$file" && cat "$file" > /dev/null
267   after resume. swapoff -a; swapon -a may also be useful.
279       running system, user asks for suspend-to-disk
293       suspend(PMSG_SUSPEND): suspend devices so that we can power off
295       turn the power off
301       running system, user asks for suspend-to-disk
304       but with resume-from-initrd, no one knows)
321   First of all: it is not a replacement for dm-crypt encrypted swap.
360   swsusp-and-swap-files.txt for details.
385   What information is useful for debugging suspend-to-disk problems?
397   How can distributions ship a swsusp-supporting kernel with modular
402   /sys/power/resume file from initrd. Be sure not to mount
403   anything, not even read-only mount, or you are going to lose your
410   If you want to see any non-error kernel messages on the virtual
419 	if [ $LOGLEVEL -lt 5 ]; then
424         read IMG_SZ < /sys/power/image_size
425         echo -n disk > /sys/power/state
431 	if [ $RET -ne 0 -a $IMG_SZ -ne 0 ]; then # try again with minimal image size
432                 echo 0 > /sys/power/image_size
433                 echo -n disk > /sys/power/state
448   In fact, even with "-o sync" you can lose data if your programs have
450   or if you disconnect before the device finished saving data you wrote.
455   Your system might well support low-power modes for its USB controllers
457   modes like "suspend-to-RAM" or "standby".  (Don't write "disk" to the
458   /sys/power/state file; write "standby" or "mem".)  We've not seen any
469   There is a work-around for this problem.  For more information, see
470   Documentation/driver-api/usb/persist.rst.
473   Can I suspend-to-disk using a swap partition under LVM?
481     echo -n "$major:$minor" > /sys/power/resume
496   for 2.6.15 (by saving more data we can get more responsive system
499   There's the /sys/power/image_size knob that controls the size of the
500   image.  If you set it to 0 (eg. by echo 0 > /sys/power/image_size as
502   slow, take a look at suspend.sf.net -- userland suspend is faster and