No, it does not, the only way right now (At least up to 12.10) is to actually add the
discard option to your
/etc/fstab file like mentioned here: How to enable TRIM?
After rebooting it should be enabled. I tested the only SSD I have right not, an Intel 520 120GB and in 12.04 it does not activate automatically. This also includes the Beta 1 of 12.10. And with this in mind, I might just add that I am thinking that on 12.10 Final, it will be the same, so a manual approach is the only way right now.
The good thing is, after upgrading a kernel in any version of Ubuntu, the discard option stays there. So at least I don't have to turn it on every time I update a kernel.
The real question would be: Why trim is not enabled by default?
And I guess it would actually depend on several factors including:
- What file system to use? (Not all file systems support TRIM)
- What SSD to use? (Some are not good with TRIM. Some don't need TRIM)
- Will RAID be used? (There are several RAID issues when using TRIM)
- What performance impact will have? (Negative, Positive. This varies depending on SSD and file system in use)
So I guess with all of this doubts, the option for one to test it out ourselves is left with the manual approach and to see if there is an actual benefit. I can say that the benefit in an Intel 520 with and without Trim is very little, at least in my case.