I have a SanDisk SSD P4 32GB and I use ext4. Ubuntu 14.04.

I read that I should execute the trim command from time to time, however, this command doesn't work on my machine:

```
# LANGUAGE=en_US:en fstrim /
fstrim: /: FITRIM ioctl failed: Operation not supported

```

I already have discard mount option, but my other computer with OpenSUSE took 30 minutes when asked to fstrim for the first time, suggesting discard option did not function since installation 6 months ago. I intend to trim my Ubuntu machine too to see whether discard worked.

I googled for 30 minutes. All "answers" either say you should upgrade to ext4 or you should use root and OP says "Oh it then works thanks.". I already did both.