[CM10.1] Using swap without repartitioning

[Guest kedazo]

ZTE Blade 3 has a plenty of space on /data partition, so i decided

to not to repartition my SD card, instead i use a file on /data as swap partition.

Sometimes the swap seems to help, at least i have less out-of-memory cases...

So here is the trick.

First you have to make a swapfile (you can do it on your SD card as well),

use adb shell and su to become root (to have access to /data/local)

# dd if=/dev/zero of=/data/local/swapfile bs=1048576 count=400 #400MB

# mkswap /data/local/swapfile

Then you have to write a script which enables the swap during boot, lets use userinit.sh for the filename, and (adb) push it to /data/local this script will be called automatically by the CyanogenMod init.d at the boot.

#!/system/bin/sh

L="log -p i -t swap"

SWAPFILE=/data/local/swapfile


$L "Activating SWAP ..."

if [ -f $SWAPFILE ];

then

/system/xbin/swapon $SWAPFILE

$L "SWAP activated."

else

$L "SWAP not activated. ($SWAPFILE not exists)"

fi

Finally lets add an executable bit to the script (adb shell and su again) (and you can start it manually right now, so no need for reboot)

# chmod 0777 /data/local/userinit.sh

# /data/local/userinit.sh

And now you can check if it it succeed:

# free -m | grep Swap										

Swap:	 409596	 42176	 367420

I tried with this CyanogenMod build, but this trick may works with the other CMs too:

http://www.modaco.co...01-android-422/

[Guest peetu20]

Thanks much, seems to work fine with cm10 :D

[Guest bamdad]

don't you think this will reduce the lifespan of the built-in flash memory? since it's not (easily) replaceable, i'm worried about wearing it out faster with all the constant read-writes..

[Guest leripe]

don't you think this will reduce the lifespan of the built-in flash memory? since it's not (easily) replaceable, i'm worried about wearing it out faster with all the constant read-writes..

Of course it will reduce it more than without it.

[Guest shadowprince94]

I did it with minor changes, like this:

 

First you have to make a swapfile (you can do it on your SD card as well),
use adb shell and su to become root (to have access to /data/local)
# dd if=/dev/zero of=/cache/swapfile bs=1048576 count=200
# mkswap /cache/swapfile
Then you have to write a script which enables the swap during boot,
lets use userinit.sh for the filename, and (adb) push it to /data/local
this script will be called automatically by the CyanogenMod init.d at the boot.
#!/system/bin/sh
L="log -p i -t swap"
SWAPFILE=/cache/swapfile

$L "Activating SWAP ..."
if [ -f $SWAPFILE ];
then
/system/xbin/swapon $SWAPFILE
$L "SWAP activated."
else
$L "SWAP not activated. ($SWAPFILE not exists)"
fi
Finally lets add an executable bit to the script (adb shell and su again)
(and you can start it manually right now, so no need for reboot)
# chmod 0777 /data/local/userinit.sh
# /data/local/userinit.sh

 

And, at the last step I got this: https://drive.google.com/file/d/0B68upf_9I8KaNXNXSHpkS3l0cnc/edit?usp=sharing

Can anyone help pls?

Edited November 3, 2013 by shadowprince94

[Guest Krityu]

Same problem:

sh: userinit.sh: not found

 

or
 

127|root@atlas40:/data/local # sh userinit.sh
sh userinit.sh
: not found[4]:
userinit.sh[13]: syntax error: 'fi' unexpected