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Tankman六四
Asked: 2014-08-15 08:50:53 +0800 CST

fstrim does not work for ext4 as root

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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.

ext4

2 Answers

  1. If you are using LVM and/or LUKS, then you need to:

    • add the discard option in your /etc/crypttab and /etc/fstab
    • ensure that issue_discards = 1 is set in your /etc/lvm/lvm.conf
    • rebuild your initramfs
    • then reboot

    (source)

    • 3
  2. Best Answer

    Is trim actually supported by your SSD ? Type 

    sudo hdparm -I /dev/sda | grep TRIM

    (assuming sda is your drive).

    Is there a line saying that TRIM is supported ?

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