Only the USG6510E/6510E-POE/6530E support this command.
After an SD card is removed and inserted again, the device can automatically identify the SD card and mount the file system. Therefore, you do not need to run the sd-card online command. However, if the SD card is not removed from the device after the sd-card offline command is executed, you need to run the sd-card online command to ensure that the SD card logs in and logs and reports are generated in a timely manner.
After you run the sd-card online command, run the display sd-card information command to view the SD card file system status. The SD card is available only when its status is Mounted.