Difference between revisions of "FailSafe"

Revision as of 02:58, 26 August 2013

Introduction of FailSafe Mode

ms14 has a FailSafe mode which can be used to recovered the devices from various problems such as:

• Update a mis-configured firmware version.
• Mis-configure network parameters cause devices accessible.
• Forgot password and need to re-flash the device to get a working unit.

Activating FailSafe Mode

Make sure your PC is connected to the LAN port of ms14. ms14's ip is 192.168.1.1 so make sure your PC are in the same network.

1. Power on ms14
2. Wait for around 15 seconds and then push toggle button and release. (Or ping 192.168.1.1 continuously and push toggle button once ping get reply)

When ms14 is in failsafe mode, it has ip 192.168.1.1 and available for telnet access.

Commands in Failsafe Mode

firstboot Command

After connecting with telnet, the filesystem you see is what will be restored if you just proceed with the 'firstboot' command. This will restore the configure to factory default (according to the firmware load in the device).

Check /etc/config/network to see what IP will be used.

Enter "firstboot" at the prompt to reset the router to default.

Restart with "reboot -f" or by power cycling (simple 'reboot' command will not work)

The device will come up on the original IP address(es).

A typical session looks like this:

 root@(none):/# firstboot
 Unlocking rootfs_data ...
 Erasing rootfs_data ...
 root@(none):/# reboot -f

Unlocking and erasing rootfs_data typically takes several seconds to complete.

mount_root Command

The root file system in failsafe mode is the only the SquashFS partition.

The JFFS2 is not present. To mount JFFS2 in read-write mode run mount_root.

Use this command to mount the last used file system and to allow you to attempt to repair it.

For example:

In case you forgot your password, you need to set a new one using the 'passwd' command

In case you forgot the routers IP address, you can get it with the command:

     uci get network.lan.ipaddr

You can edit /etc/config/network to set up a working network configuration.

Reference

http://wiki.villagetelco.org/OpenWrt_Failsafe_Mode_and_Flash_Recovery