Feature #7938

disable LBA weighting on files and SSDs

Added by James Blachly almost 2 years ago. Updated over 1 year ago.

Status:NewStart date:2017-03-05
Priority:NormalDue date:
Assignee:James Blachly% Done:

100%

Category:zfs - Zettabyte File SystemEstimated time:1.00 hour
Target version:-
Difficulty:Bite-size Tags:complete, needs-review

Description

ZFS on Linux has had a feature "Disable LBA weighting on SSD" since August 2015:
http://open-zfs.org/wiki/Features#Disable_LBA_Weighting_on_files_and_SSDs
https://github.com/zfsonlinux/zfs/commit/fb40095f5f0853946f8150481ca22602d1334dfe

Because we have the device property "device-solid-state" we can port this over. In addition, we can add detection for virtio vioblk device, which should also not use LBA weighting.

On linux, block devices have a "non-rotational" property, so this is a one liner in vdev_disk.c:
v->vdev_nonrot = blk_queue_nonrot(bdev_get_queue(vd->vd_bdev));

We do not, so the checks are a little bit more cumbersome but doable (check device-solid-state != 0 and inqury-vendor-id==Virtio separately)

Parenthetically, perhaps we should have a "non rotational" property for block devices?


Related issues

Blocked by illumos gate - Bug #7940: provide device-rotational property Closed 2017-03-05

History

#1 Updated by Yuri Pankov almost 2 years ago

  • Blocked by Bug #7940: provide device-rotational property added

#2 Updated by Yuri Pankov over 1 year ago

James, are you still working on this?

#3 Updated by James Blachly over 1 year ago

Yuri Pankov wrote:

James, are you still working on this?

Yes -- thanks for ping. Got busy with work. Patch is done but I need to do a clean nightly build.

#4 Updated by Yuri Pankov over 1 year ago

  • Subject changed from Port ZOL #3712 disable LBA weighting on files and SSDs to disable LBA weighting on files and SSDs

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