This article can be used to see kernel messages related to the USB. Messages can be related to insertion, removal etc.

There are many scenarios in which we want to know the USB label; scenarios like upgrade, transferring files, etc.

For example, during the upgrade procedure, sometimes you may not see any USB related messages on the CLI output, when you plug the USB in.

Or perhaps you need to find the reason why SRX is not able to detect the USB.

There are lot of messages generated by kernel.

dmesg is used to review these messages at later date.

Use the dmesg| grep "da" command at the shell prompt to see kernel messages related to USB events.

If you are only concerned about USB related messages, you can filter by the use of grep.

For example:

Messages on Insertion of a USB:

root@SRX1400-1% dmesg | grep "da"
da0 at umass-sim0 bus 0 target 0 lun 0
da0: <SanDisk Cruzer Pop 1.26> Removable Direct Access SCSI-5 device
da0: 40.000MB/s transfers
da0: 7633MB (15633408 512 byte sectors: 255H 63S/T 973C)

Messages on Removal of a USB:
(da0:umass-sim0:0:0:0): lost device
(da0:umass-sim0:0:0:0): removing device entry