Re: [gentoo-user] hibernate... /bin/echo: write error: No such device

[Jack <ostroffjh@users.sourceforge.net>]

On 2022.08.03 17:30, Walter Dnes wrote:
>   Checking the obvious;  "make menuconfig"...
> 
> > Power management and ACPI options
>     [ ] Suspend to RAM and standby
>     [*] Hibernation (aka 'suspend to disk')
>     [*]   Userspace snapshot device
>     (/dev/sda2) Default resume partition
> 
>   Checking where/how it'll suspend...
> 
> cat /sys/power/state
> disk
> 
>   So far, so good.  I was ssh'd in and I shrank the font size to
> "unreadable" and ran "hibernate --verbosity=4", to get debug level
> output.  It captured "only" the last 519 lines of output, attached as
> errlog.txt.gz which I copy/pasted to vim on my desktop.
> 
> Line 305 is where "DoSysfsPowerStateSuspend" starts
> Line 317 is the "/bin/echo -n disk" statement
> 
>   Next we look at file  
> /usr/share/hibernate/scriptlets.d/sysfs_power_state
> which has a short function DoSysfsPowerStateSuspend().  Anyone  
> remember
> ye old dayes of FORTRAN, where you'd throw in print statements to  
> debug
> errors?  I've added a few debug statements, like so...
> 
> DoSysfsPowerStateSuspend() {
>     if [ -z "$SYSFS_POWER_STATE_NO_SUSPEND" ] ; then
>         vecho 1 "$EXE: Activating sysfs power state  
> $USING_SYSFS_POWER_STATE ..."
> echo "1 ==> $USING_SYSFS_POWER_STATE"
> echo "2 ==> $SYSFS_POWER_STATE_POWERDOWN_METHOD"
> echo "3 ==> $SYSFS_POWERDOWN_METHOD_FILE"
> echo "4 ==> $SYSFS_POWER_STATE_FILE"
>         [ -n "$SYSFS_POWER_STATE_POWERDOWN_METHOD" ] && \
>             [ -f "$SYSFS_POWERDOWN_METHOD_FILE" ] && \
>             /bin/echo $SYSFS_POWER_STATE_POWERDOWN_METHOD >  
> $SYSFS_POWERDOWN_METHOD_FILE
>         /bin/echo -n $USING_SYSFS_POWER_STATE >  
> $SYSFS_POWER_STATE_FILE
>     else
>         vecho 1 "$EXE: Not actually suspending (--no-suspend given)"
>     fi
>     return 0
> }
> 
>   The output from hibernate is...
> 
> 1 ==> disk
> 2 ==>
> 3 ==> /sys/power/disk
> 4 ==> /sys/power/state
> /bin/echo: write error: No such device
> 
>   No powerdown method?  I added "resume=/dev/sda2" to lilo.conf and
> re-ran lilo.  And now we cross the boundary from the ridiculous to the
> totally utterly sublime.
> 
> [thimk][root][~] cat /sys/power/state
> disk
> [thimk][root][~] echo disk > /sys/power/state
> -bash: echo: write error: No such device
> [thimk][root][~] cat /sys/power/state
> disk
> 
> WTF!!!
> 
> --
> Walter Dnes <waltdnes@waltdnes.org>
> I don't run "desktop environments"; I run useful applications
No answers, but some thoughts.  Remember the files in /sys/power are  
not real files, they are created by sysfs (or something relying on  
sysfs.)  I wonder if something in the sysfstools package will let you  
dig into why /sys seems or claims not to be there.  The other  
possibility is that whatever actual program is trying to do that write  
has a bug and is recognizing some other condition as a "no such device"  
error, but I suppose your last test disproves that.