SRX240 Services Gateway Boot Devices and Dual-Root Partitioning Scheme
This topic includes the following sections:
Boot Devices
The SRX240 Services Gateway can boot from the following storage media (in the order of priority):
- Internal NAND flash (default; always present)
- USB storage key (alternate)
Dual-Root Partitioning Scheme
Dual-root partitions allow the SRX240 Services Gateways to remain functional if there is file system corruption and facilitate easy recovery of the corrupted file system.
The dual-root partitioning scheme keeps the primary and backup JUNOS Software 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 Software image located in the other root partition and remain fully functional.
When the SRX240 Services Gateway powers up, it tries to boot the JUNOS Software from the default storage media. If the device fails to boot from the default storage media, it tries to boot from the alternate storage media. With the dual-root partitioning scheme, the SRX240 Services Gateway first tries to boot the JUNOS Software from the primary root partition and then from the backup root partition on the default storage media. If both primary and backup root partitions of a media fail to boot, then the device tries to boot from the next available type of storage media. The SRX240 Services Gateway remains fully functional even if it boots the JUNOS Software from the backup root partition of storage media.
 | Note: SRX Series devices that ship from the factory with JUNOS Release 10.0 are formatted with the dual-root partitioning scheme. |
The SRX240 Services Gateway that are running JUNOS Release 9.6 or earlier use the single-root partitioning scheme. While upgrading these devices to JUNOS Release 10.0, you can choose to format the storage media with dual-root partitions (strongly recommended) or retain the existing single-root partitioning.
For instructions on upgrading to JUNOS Release 10.0, see the SRX Series Release Notes.
