USB swapfile creation

Latest revision as of 04:16, 17 December 2012

HOWTO set up a memory swapfile on a USB stick

*NOTE This feature should only be set up by users with large z-wave networks and some knowledge of Linux internal commands. The functionality has been tested by some beta testers if the userforum at http://forum.mios.com, but using the feature should still be done with caution.

[edit] Prerequisites

• Vera 2 hardware
• Vera firmware 1.1.1245 or later
• USB stick attached to Vera

[edit] Introduction

Heres a short manual on how to set up a memory swap file on a USB stick to allocate more memory for your Vera. This is an additional feature once you have set up USB logging for Vera as described here: Store_logs_USB

The instructions contain commands for 4 indivudual steps.

Data description for 64Mb swapfile Creating swapfile Start using swapfile Stop using a swapfile.

Please note that rebooting Vera will require a manual start of the swapfile. Upgrading Vera's firmware will require setting up the swapfile from scratch as per instructions below.

[edit] Instructions

To set up a swapfile for Vera to use after you have have enabled to store logs on a USB stick as described here: Store logs USB it is required to SSH into your Vera. This procedure is explained here: Logon Vera SSH.

Once you are at the SSH commandline, enter these commands one by one. Please note that the forst command can take a few minutes to complete, depending on the speed of your USB stick.

1. Data description for 64Mb swapfile for the filesystem:

dd if=/dev/zero of=/tmp/log/cmh/swapfile bs=1024 count=65536

2. Creating the actual swapfile:

mkswap /tmp/log/cmh/swapfile	

3. Start using the newly created swapfile:

swapon /tmp/log/cmh/swapfile

How to test if swap is enabled: Re-issue the above command and if the file shows busy, then swap is enabled

swapon /tmp/log/cmh/swapfile
swapon: /tmp/log/cmh/swapfile: Device or resource busy

If for some reason you would like to stop Vera using the swapfile use the following command after SSH-ing into Vera:

swapoff /tmp/log/cmh/swapfile

4. Persistent Swap after reboot: Edit /etc/init.d/usb and insert the following line in the appropriate place:

swapon /tmp/log/cmh/swapfile

Shown below in /etc/init.d/usb

#!/bin/sh /etc/rc.common
# Copyright (C) 2006 OpenWrt.org

START=39
start() {
        [ -d /proc/bus/usb ] && {
                /bin/mount -t usbfs none /proc/bus/usb
                /sbin/swapon /tmp/log/cmh/swapfile
        }
}

[edit] References

please find more info here:
http://wiki.openwrt.org/doc/howto/usb.storage