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I'm running Ubuntu 10.04 and lshw shows a "SAMSUNG SSD UM41". Thanks to SU, I determined previously that my system isn't using TRIM.


  • my BIOS SATA settings should say AHCI (check)
  • kernel .28+ supports it (using .32)
  • ext4 supports it (using ext4)
  • my disk manfuacturer says I support it
  • hdparm -I /dev/sda should say that I'm using TRIM (fail! using hdparm 9.30)

How do I determine what's preventing TRIM from being used, and how might I remedy this?

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Does hdparm -I explicitly say you're not using TRIM, or does it not mention it at all? The reason I ask is I believe you need a relatively recent version of hdparm. – Karl Bielefeldt Aug 27 '10 at 20:02
It doesn't mention it at all, but I was using 9.30 which I believe should be recent-enough. – Yang Dec 4 '10 at 3:38
up vote 1 down vote accepted

kernel .28 may have included experimental support, but only from 2.6.33 on it is part of the mainstream kernel. So update your kernel ... or maybe you can activate the experimental stuff somehow (don't ask me).

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I followed this procedure with 2.6.35-32-generic and Ubuntu 10.04.

There exist various reasons why we might want to install the newer 2.6.35 kernel that ships with Ubuntu 10.10 on Ubuntu 10.04. Some would want TRIM support, others would want enhanced power saving. Whatever the case the Ubuntu Team has provided an easy way to accomplish this task: All we need to do is launch a Terminal and type in:

sudo apt-get update && sudo apt-get install linux-image-generic-lts-backport-maverick linux-headers-generic-lts-backport-maverick

Reboot the computer. Now we should be running Linux kernel 2.6.35.

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