Juniper SRX240 Series, Hardware Manual

Page: 28 / 198

SRX240 Services Gateway Boot Devices and Dual-Root Partitioning Scheme
This topic includes the following sections:
• Boot Devices on page 10
•
Dual-Root Partitioning Scheme on page 10
Boot Devices
The SRX240 Services Gateway can boot from the following storage media (in the given
order of priority):
•
Internal NAND flash memory (default; always present)
• USB storage device (alternate)
Dual-Root Partitioning Scheme
Dual-root partitions allow 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 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.
When the services gateway powers up, it tries to boot Junos OS from the default storage
media. If the services gateway fails to boot from the default storage media, it tries to
boot from the alternate storage media. With the dual-root partitioning scheme, the
services gateway first tries to boot Junos OS from the primary root partition and then
from the backup root partition on the default storage media. The services gateway
remains fully functional even if it boots Junos OS from the backup root partition of storage
media.
NOTE: SRX Series Services Gateways that ship with Junos OS Release 10.0
or later are formatted for the dual-root partitioning scheme.
SRX240 Services Gateways that are running Junos OS Release 9.6 or earlier use the
single-root partitioning scheme. While upgrading these services gateway to Junos OS
Release 10.0 or later, 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 OS Release 10.0 or later, see the following guides:
• Initial Configuration for Security Devices
• Monitoring and Troubleshooting for Security Devices
Copyright © 2015, Juniper Networks, Inc. 10
SRX240 Services Gateway Hardware Guide