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Out-of-the-Box, Ubuntu 14.04 LTS To Support TRIM On SSDs

Posted by timothy on from the keep-it-snappy dept.

First time accepted submitter Maurits van der Schee writes "Where in older versions you had to add a cron job calling "fstrim" or mounting with the "discard" option in fstab, the new LTS (Long Term Stable) version of Ubuntu Linux will automatically enable TRIM for your SSD. Good news for hardware enthusiasts!"

7 of 133 comments (clear)

  1. Stable? by Anonymous Coward · · Score: 5, Informative

    "LTS is an abbreviation for "Long Term Support"."

  2. Taking too long by Anonymous Coward · · Score: 5, Insightful

    This is way overdue.

    It's also taking too long for file systems that provide snapshot features to become mainstream and default as well. And no, LVM snapshots aren't good enough.

    No, I'm not going to write the patches. They wouldn't be accepted in any case. Fundamental features such as the IO stack and file systems are now the exclusive purview of well-heeled outfits like Red Hat, Oracle, Intel, OSDL, etc. and and their stable of full time developers.

    They just need to do their jobs and get it done.

    1. Re:Taking too long by darkpixel2k · · Score: 5, Funny

      I've been choosing btrfs through the debian installer for at least a couple of years now.

      Dude you so have to try ZFS. It's aweso--

      Yes, I know it's not as awesome as ZFS, but it still beats mdraid and lvm.

      Oh--sorry. Got ahead of myself there. Good thing you stopped me in time.

      --
      There's no place like ::1 (I've completed my transition to IPv6)
  3. WHAT THE FUCK ARE YOU DOING?! by Anonymous Coward · · Score: 5, Funny

    HOLY FUCK, MAN! JUST WHAT THE HELL DO YOU THINK YOU'RE DOING?!?!?!

    This is Slashdot, for crying out loud. How DARE you bring facts and correct information to the discussion here! THAT IS NOT ALLOWED! You just can't do that! FUCK!

  4. TRIM not always good by girlintraining · · Score: 5, Interesting

    the new LTS (Long Term Stable) version of Ubuntu Linux will automatically enable TRIM for your SSD. Good news for hardware enthusiasts!"

    And terrible news for encryption experts. Enabling TRIM tells your adversary which sectors contain data and which don't. It's a great asset to cryptanalysis and also destroys plausible deniability that there's a filesystem present on the drive, and how much data is present in it -- thus eliminating the "shadow volume" option of Truecrypt and others.

    --
    #fuckbeta #iamslashdot #dicemustdie
    1. Re:TRIM not always good by Anonymous Coward · · Score: 5, Interesting

      No, YOU clearly don't know what you're talking about, and yet are arrogant as all hell.
      The problem arises from the fact that while HDDs have only 2 operations (read, write) and therefore have no distinction outside the file-system of what is "free" and what is "allocated", SSDs have 3 (read, write, free), because SSDs label sectors as "free" or "allocated" (that is, the hardware itself, not just the file-system). So for a standard HDD encryption, the procedure goes: overwrite hard drive with random data, create encrypted partition, install OS on encrypted partition (last step optional, of course). What this accomplishes is that an attacker who examines the disk can't tell the difference between what is and isn't written to, since the unwritten data is random and the written data is encrypted (i.e. indistinguishable from random, if done correctly). On a TRIM-enabled SSD though, the OS sees all these unused sectors and proceeds to mark them as Free. That is a huge fucking problem, for the roughly the reasons the GP stated. In particular, it's egregiously bad for users of hidden volumes, since that hidden volume will never be TRIMed, and the attacker who can rubber hose your outer volume can see a chunk of disk that hasn't been trimmed, yet isn't allocated in the partition you gave them. They can now rubber hose THAT partition as well, whereas previously there was no way to know it even existed (in theory at least, the cryptsetup guys don't buy that).

      If you don't believe this is an issue, then ask the Truecrypt devs:
      http://www.truecrypt.org/docs/trim-operation

      or the LUKS/dm-crypt devs:
      http://asalor.blogspot.com/2011/08/trim-dm-crypt-problems.html

      Please be more respectful in the future, as we're wrong more often than we like to think.

    2. Re:TRIM not always good by LordLimecat · · Score: 5, Insightful

      Dude, youre overstating the threat.

      If the drive is encrypted, theres no more or less threat from brute-forcing.

      From a plausible deniability standpoint, Im not terribly sure how helpful that is ANYWAYS. If someone wants to know if youre using truecrypt, they could, I dont know, look at the MBR and see whether its using the Truecrypt bootloader. The idea that you can say "What partition?" when goons grab your mysteriously unreadable laptop is laughable. Im sure there are super corner cases where that would be helpful, but generally if youre being held by the sorts of people who have the means and ability to do rubber hose cryptography, theyre not going to put up with your BS about "but wait look i gave you a password that boots to an Ubuntu partition which only accounts for 1/2 of the drive's size, and has no data worth encrypting whatsoever!"

      Being involved with multiple organizations which employ encryption for very different reasons, none of them use plausible deniability / hidden encryptions; Id reckon because its not terribly helpful, or even plausible.