Problem with automount usb sd reader

[dave jones]

Hello,

I have a usb-based sdcard reader in my computer:
umass0: <Generic USB Storage, class 0/0, rev 2.00/94.51, addr 2> on usbus4
umass0:  SCSI over Bulk-Only; quirks = 0x0000
umass0:2:0:-1: Attached to scbus2
(probe0:umass-sim0:0:0:0): TEST UNIT READY. CDB: 0 0 0 0 0 0
(probe0:umass-sim0:0:0:0): CAM status: SCSI Status Error
(probe0:umass-sim0:0:0:0): SCSI status: Check Condition
(probe0:umass-sim0:0:0:0): SCSI sense: UNIT ATTENTION asc:28,0 (Not
ready to ready change, medium may have changed)
da0 at umass-sim0 bus 0 scbus2 target 0 lun 0

If I want to mount the sd card, I have to run "true > /dev/da0" first
to create /dev/da0s1 device node.
In order to automount, I was trying to add the following lines in
/etc/devd.conf but doesn't work.
attach 10 {
        device-name "umass0";
        action "true > /dev/da0; mount /dev/da0s1 /mnt";
};

Any solutions? Thank you.

BR.
Dave.