JunOS : Versions running on dual partitions are not same
This appears on the console when booting a Juniper device:
WARNING: JUNOS versions running on dual partitions are not same
This will happen on an upgrade of JunOS. To resolve this issue, make sure you are currently booted on the slice with the version you want to run into production. To find out, run the following command :
show system snapshot media internal
And (on an SRX) you will see something like this:
Information for snapshot on internal (/dev/da0s1a) (backup)
Creation date: Jun 31 11:22:20 2020
JUNOS version on snapshot:
junos : 15.1X49-D141-domestic
Information for snapshot on internal (/dev/da0s2a) (primary)
Creation date: Oct 9 16:26:58 2020
JUNOS version on snapshot:
junos : 15.1X49-D211-domestic
As we can see, we are currently running on the secondary slice (/dev/da0s2a), running 15.1X49-D211-domestic. The primary slice (/dev/da0s1a) is out of sync.
In that case, the healthy slice (/dev/da0s2a) and version we want to run into production is 15.1X49-D211-domestic we will replicate to the primary slice (/dev/da0s1a) using the builtin JunOS snapshot mechanism. In order to do that, we will use the following command :
request system snapshot slice alternate
NOTICE : This will format the slice marked as “backup” and copy the slice marked as “primary” to it.
Reference: