DiskTRIM - Nukama/wiki.qubes-os.org GitHub Wiki


title: DiskTRIM permalink: /wiki/DiskTRIM

VMs have already TRIM enabled by default, but dom0 doesn't. There are some security implications (read for example ​this article), but IMO not very serious.

To enable TRIM in dom0 you need:

  1. Get your LUKS device UUID:

    ls /dev/mapper/luks-*
    
  2. Add entry to /etc/crypttab (replace luks-<UUID> with the device name and the <UUID> with UUID alone):

    luks-<UUID> UUID=<UUID> none allow-discards
    
  3. Add rd.luks.allow-discards=1 to kernel cmdline (/etc/default/grub, GRUB_CMDLINE_LINUX line)

  4. Rebuild grub config (grub2-mkconfig -o /boot/grub2/grub.cfg)

  5. Rebuild initrd in hostonly mode:

    dracut -H -f
    
  6. Add "discard" option to /etc/fstab for root device

  7. Reboot the system, verify that allow-discards is really enabled (dmsetup table)

There is a ​bug affecting allow-discards option, once it will be fixed, first two steps will be no longer needed.

⚠️ **GitHub.com Fallback** ⚠️