Uploaded image for project: 'CloudStack'
  1. CloudStack
  2. CLOUDSTACK-8104

Add TRIM/Discard support to Qemu

    XMLWordPrintableJSON

    Details

    • Type: New Feature
    • Status: Closed
    • Priority: Minor
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: None
    • Component/s: KVM
    • Labels:

      Description

      Thinly provisioned volumes on storage devices continue to grow because the storage device has no idea of which blocks are in use.

      For SSDs the TRIM/Discard feature was invented to give free/unused blocks back to the flash device, but this can also be used for Qemu.

      Ceph's RBD for example supports trimming so that volumes can shrink again when blocks are no longer in use.

      This is supported since Qemu 1.5, but since 1.6 it also works for QCOW2 images.

      It however requires the new virtio-scsi to work optimal, so it requires some changes.

      For more information see:

        Attachments

          Issue Links

            Activity

              People

              • Assignee:
                widodh Wido den Hollander
                Reporter:
                widodh Wido den Hollander
              • Votes:
                2 Vote for this issue
                Watchers:
                3 Start watching this issue

                Dates

                • Created:
                  Updated:
                  Resolved: