User`s guide

Boot File Location Information
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AlterPath OnSite Administrator’s and User’s Guide
Boot File Location Information
The information in this section is needed to understand how to configure
booting through the Web Manager, as described in
“Configuration>System>Boot Configuration” on page 351. This information
is also needed for troubleshooting, to give an administrator who has the root
password enough background to be able to boot from an alternate image if the
need arises and if the Web Manager is not available.
The OnSite uses a U-Boot boot loader that resides in soldered flash memory
and that automatically runs at boot time. U-Boot boots the OnSite from an
image whose location is configurable. The image can reside either in
removable flash memory on the OnSite or on a boot server on the network.
Each image on the removable flash has three separate file systems mounted on
three Linux partitions. The first partition for each image contains the kernel,
the second partition contains the root filesystem mounted read only, and the
third partition contains the configuration files mounted read-write.
For more about U-Boot in general, go to: http://sourceforge.net/projects/u-
boot.
The OnSite boots from alternate images as described below.
• The OnSite initially boots from a software image referred to as “image1,”
which is stored in three partitions on the removable flash (hda1, hda5,
and hda7).
• The first time you download and install a new software version from
Cyclades, the new image is stored as “image 2” in another set of three
identical partitions on the removable flash (hda2, hda6, and hda8), and
the configuration is changed to boot the OnSite from “image2.”
• The second time you download a new software version, the latest image is
stored as “image1” in the first set of three partitions, and the OnSite
configuration is changed to boot from “image1.”
• Subsequent downloads are stored following the same pattern, alternating
“image1” with “image2.”
Each image has three separate filesystems mounted on three Linux partitions.
Refer to the following text and figure explaining partition numbers if needed
for understanding some of the instructions in the rest of this
chapter. As
illustrated in the following figure, the first partition for each image contains
the Linux kernel, the second partition contains the root-mounted filesystem