I have installed one SSD disk (Micron C400-MTFDDAC128MAM) in an external USB 3.0 enclosure. Now I want use this disk as a second disk in my laptop with Ubuntu 12.04. The disk is working, but I want to use TRIM support which is not working as expected.

Checking for TRIM support:

user@server:~$ sudo hdparm -I /dev/sdc | grep -i TRIM

       *    Data Set Management TRIM supported (limit 8 blocks)

       *    Deterministic read data after TRIM

Disk was mounted with the following options:

/dev/sdc1 on /media/MICRON type ext4 (rw,nosuid,nodev,uhelper=udisks)

But when I run the TRIM command manually, I get an error:

user@server:~$ sudo fstrim -v /media/MICRON/

fstrim: /media/MICRON/: FITRIM ioctl failed: Operation not permitted

I used this disk before as an internal disk and TRIM was working.

Here are some USB details:

[ 1039.248050] usb 4-1: new SuperSpeed USB device number 4 using xhci_hcd

[ 1039.265597] scsi8 : usb-storage 4-1:1.0

[ 1041.547879] scsi 8:0:0:0: Direct-Access     C400-MTF DDAC128MAM       0509 PQ: 0 ANSI: 5

[ 1041.549134] sd 8:0:0:0: Attached scsi generic sg2 type 0

[ 1041.550511] sd 8:0:0:0: [sdc] 250069680 512-byte logical blocks: (128 GB/119 GiB)

[ 1041.550778] sd 8:0:0:0: [sdc] Write Protect is off

[ 1041.550785] sd 8:0:0:0: [sdc] Mode Sense: 23 00 00 00

[ 1041.552520] sd 8:0:0:0: [sdc] No Caching mode page present

[ 1041.552528] sd 8:0:0:0: [sdc] Assuming drive cache: write through

[ 1041.554029] sd 8:0:0:0: [sdc] No Caching mode page present

[ 1041.554035] sd 8:0:0:0: [sdc] Assuming drive cache: write through

[ 1041.678373]  sdc: sdc1

[ 1041.679982] sd 8:0:0:0: [sdc] No Caching mode page present

[ 1041.679991] sd 8:0:0:0: [sdc] Assuming drive cache: write through

[ 1041.679997] sd 8:0:0:0: [sdc] Attached SCSI disk

How to find out if the mass storage device uses the UASP (USB Attached SCSI Protocol) which should support TRIM?