When SFM is offline using the CLI, upon doing a commit for any changes made it is observed that the SFM reboots and then goes online. This can create issues if the SFM was intentionally kept offline. This is not a Junos bug but is the expected behavior.
By default, if you use the request chassis sfm CLI command to take an SFM offline, the SFM attempts to restart when you enter a commit CLI command. To prevent a restart, you can configure an SFM to stay offline. This feature is useful for repair situations. To configure an SFM to stay offline, include the SFM statement at the [edit chassis] hierarchy level:
request chassis sfm
[edit chassis] sfm slot-number { power off; }
[edit chassis] sfm 3 power off;
show chassis sfm
user@host# show chassis sfm Temp CPU Utilization (%) Memory Utilization (%) Slot State (C) Total Interrupt DRAM (MB) Heap Buffer 0 Online 34 2 0 64 16 47 1 Online 38 2 0 64 16 47 2 Online 42 2 0 64 16 47 3 Offline --- Configured power off ---