Before pushing a Junos OS upgrade to a router at a rural head-end, an engineer wants to confirm there's enough free space on the device's local storage to hold the new software image. Which command checks that?
Select an answer to reveal the explanation.
Short Explanation
You wouldn't start downloading a large file onto a drive without checking there's room for it first. show system storage is that free-space check for a router — confirming there's enough room before the new OS image lands, so the upgrade doesn't fail partway through.
Full Explanation
show system storage reports filesystem-level usage and free space across the device's storage partitions, which is exactly the information needed to confirm a new Junos OS package — often a sizable file — will actually fit before it's copied to the router and the install begins. show version reports the currently running software version and general model information; it's a useful pre-upgrade check for confirming the starting point, but it has no visibility into available disk space. show chassis hardware inventories physical components like FPCs and PICs and their serial numbers, which is unrelated to filesystem capacity. show system snapshot is a real and different command entirely — rather than checking space, it actively creates a backup copy of the current software and configuration onto backup storage media, which itself consumes space and is a separate precaution some engineers take before an upgrade, not a capacity check. A caveat worth noting: insufficient space is a common, avoidable cause of a failed or stalled installation, especially on devices accumulating old log files and unused images over years of service. A concrete check: run show system storage, and if free space is tight, run request system storage cleanup before copying the new image over.