This article explains the warning message encountered during an SRX device boot: "JUNOS versions on dual partitions do not match (/dev/da0s2a)."

During the SRX boot process, the following warning message appears in the bootup logs:

WARNING: JUNOS versions running on dual partitions are not the same. /dev/da0s2a

This is expected behavior. When upgrading an SRX device, the upgrade process updates the backup partition and then designates it as the new primary partition. The previous primary partition is then converted into the new backup partition, which retains the older Junos version. Since the versions in the primary and backup partitions differ, this warning appears.

Having different Junos versions in the backup partition is intended for software rollback purposes. However, if the new version is stable and you want both partitions to have the same Junos version, run the following command:

request system snapshot slice alternate