SSD Device mounted: N ?

Hi,

On my FortiGate 1000C, Symptoms are no more Logs since a couples of days.  Also CPU and Memory usage are getting High.

When I do the CLI:

# diag hardware deviceinfo disk:

Device S0          59.6 GB      ref: 0          ATA SAMSUNG 470 Seri (SSD) [HDD1]                         ] partition 1      59.6 GB      ref: 1          label: 545A45490DAC05F6   [ dev: /dev/sda1  major: 8  minor: 1  free: 0MB  mounted: N ]    <========= Not Mounted ?

My question: 

    => Is there a command to "mount" that device ?  Or Do I have to Format ?

    => That SSD was mounted last week... Failed SSD ?

FortiOS-40-MR3

Thanks.