A recent storm caused us to lose power and the next time I logged in into my SRX100H2 home router, I was greeted with this warning:

***********************************************************************
**                                                                   **
**  WARNING: THIS DEVICE HAS BOOTED FROM THE BACKUP JUNOS IMAGE      **
**                                                                   **
**  It is possible that the primary copy of JUNOS failed to boot up  **
**  properly, and so this device has booted from the backup copy.    **
**                                                                   **
**  Please re-install JUNOS to recover the primary copy in case      **
**  it has been corrupted.                                           **
**                                                                   **
***********************************************************************

Luckily, the fix was easy and kudos to Juniper for implementing the two-partition system. Here’s the fix:

request system snapshot slice alternate

To verify the procedure, issue the following command:

show system snapshot media internal

The results should look something like this:

Information for snapshot on       internal (/dev/da0s1a) (backup)
Creation date: Aug 14 18:06:53 2015
JUNOS version on snapshot:
  junos  : 12.1X44-D35.5-domestic
Information for snapshot on       internal (/dev/da0s2a) (primary)
Creation date: Jul 31 11:15:08 2016
JUNOS version on snapshot:
  junos  : 12.1X44-D35.5-domestic