The information in this section is needed to understand how to configure booting through the Web Manager, as described in Configuration>System>Boot Configuration. 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.
• 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 help. As illustrated in the following figure, the first partition for each image contains the Linux kernel, the second partition contains the root-mounted filesystem (which is mounted read only), and the third partition (which is mounted read write) contains the configuration files.The previous figure also shows a configuration backup partition (/dev/hda3 in removable flash). This partition is mounted as /mnt/hda3. The
/mnt/hda3/backup directory contains compressed copies of backed up configuration files, as shown in the following screen example.
[root@ONS /]# cd /mnt/hda3/backup