User`s guide

Network Boot Options and Caveats
572
AlterPath OnSite Administrator’s and User’s Guide
Network Boot Options and Caveats
When a network boot is performed with the U-boot net_boot command,
the OnSite boots from the specified image on the specified TFTP server. The
image uses the RAMDISK as the root file system. Network boots are useful
for troubleshooting because the net-booted image can run even if the OnSite’s
flash memory is not usable.
Network boots are recommended only for troubleshooting and must not be
used for normal operation of the OnSite. For example, if you want to test a
new release of the software to make sure a problem is fixed, or if the resident
flash memory becomes corrupted, you could download the software from a
tftpboot server, and then save it to the removable flash after testing, using the
create_cf command with the appropriate options (see “Options for the
create_cf Command” on page 577).
When a network boot is performed, the system uses one of the two following
sources of configuration data:
• If the net_boot command is entered with the
configsource=factory_default option, the factory_default
configuration files are restored.
• Otherwise, the backed up configuration files from the /dev/hda3
backup partition are copied to the RAMDISK and used.
Any configuration changes made after the last backup copy was made are lost
unless the configuration files were backed up before the network boot and
then restored afterwards (see “How Configuration Files Changes Are
Managed” on page 574).
T To Replace a Boot Image From a Network
Boot in U-Boot Monitor
Mode
1. Log in as root in U-boot monitor mode.
If needed, see, ‘“To Boot in U-Boot Monitor Mode” on page 570.