Dual-Root Partitioning Scheme Overview

Junos OS Release 10.0 and later releases supports dual-root partitioning on SRX Series devices. Dual-root partitioning allow the SRX Series devices to remain functional if there is file system corruption and facilitate easy recovery of the corrupted file system.

SRX Series devices running Junos OS Release 9.6 or earlier support a single-root partitioning scheme where there is only one root partition. Because both the primary and backup Junos OS images are located on the same root partition, the system fails to boot if there is corruption in the root file system. The dual-root partitioning scheme guards against this scenario by keeping the primary and backup Junos OS images in two independently bootable root partitions. If the primary root partition becomes corrupted, the system will be able to boot from the backup Junos OS image located in the other root partition and remain fully functional.

SRX Series devices that ship with Junos OS Release 10.0 or later are formatted with dual-root partitions from the factory. SRX Series devices that are running Junos OS Release 9.6 or earlier can be formatted with dual-root partitions when they are upgraded to Junos OS Release 10.0 or later.

Note: The dual-root partitioning scheme allows the SRX Series devices to remain functional if there is file system corruption and facilitates easy recovery of the corrupted file system. Although you can install Junos OS Release 10.0 or later on SRX Series devices with the single-root partitioning scheme, we strongly recommend the use of the dual-root partitioning scheme.