Booting without the overlay file, Booting without the overlay – Znyx Networks bh5700 User Manual

Page 158

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properly attach the console cable.

Booting Without the Overlay

File

If you cannot

telnet

into the switch and Linux fails to boot, it is likely that a change saved by

zsync

has left the switch in an inaccessible state. To allow users to recover from mistakes saved

in the overlay file system, a boot argument of

–i

passed to the

init

process will stop the

untarring of the saved overlay files. As a result, the system boots to the factory-shipped
configuration.

1. Connect through the console port. During boot up, the system displays the Linux boot

string. Linux/PPC load: for 5 seconds. During the 5 second pause, enter the boot option

-i

and press Return

Linux/PPC load: root=/dev/ram init=/sbin/init -i

2. Initiating the

–i

option of

zbootcfg

.

zbootcfg –d 1 –i

3. Reboot the system. After the reboot, clear the

–i

option from the boot string. Enter the

following command:

zbootcfg –d 1

4. The reboot command will also take

-i

as an option and pass it to the Linux boot,

reboot -i

5. When the system boots, the overlay file system is returned to the factory-installed

configuration. At this point, you have a few options.

Caution: All changes you have made and saved prior to the

zsync

command

will be lost when the command executes.

a) Enter

zsync,

and the factory-installed system will be restored to your flash.

b) Restore particular files from the existing overlay. Use the

zmnt

command to mount

the overlay in a designated directory and copy back just the changes you want to keep
from the existing overlay.

For example, if you wanted to recover your /etc/hosts file from the existing
overlay, use zmnt to mount the overlay in a designated directory, like

/tmp

,

then copy /

tmp/etc/hosts

to

/etc/hosts

. Lastly, use

zsync

to save your

changes (as follows).

zmnt /tmp

cp /tmp/etc/hosts /etc/hosts

zsync /etc/hosts

6. Reboot the system.

Ethernet Switch Blade User's Guide

release 3.2.2j

page 158

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