How to activate and then verify automatic TRIM on a SSD for Ubuntu 12.04 Precise

[sudodus]

Focusing on roten's questions:

sudo fstrim -v /
With discard enabled it did nothing. Without discard enabled it reported
Code:
/mnt: 19918028800 bytes were trimmed
- Do you think that discard works also on this drive?
- Do you think that fstrim works on this drive?

I guess fstrim works (I, too, tested on a drive, that is not zeroized), and it could trim various amounts depending on how much was written and deleted).

- What do you recommend?
. discard or
. cron job with fstrim

Given the feedback from fstrim, it sound more likely to work. But I leave it to the gurus ...

[sudodus]

I found this link

http://www.buildingcubes.com/2012/10...mand-on-linux/

which claims fstrim works on ext2 and ext3, but will trim the whole unused space trimmed or not trimmed.

[loyhz2ayj-jeff]

I have read (at http://blog.neutrino.es/2013/howto-p...m-and-dmcrypt/) (see also http://askubuntu.com/questions/19191.../191945#191945) that lvm 2.02.66 that ships with 12.04 LTS does not support TRIM.

And there is no way to upgrade LVM except installing Ubuntu 13 (which you have already done). Are we stuck until 14 LTS comes out unless we want to run 13 for 9 months?