[lustre-discuss] File level erasure coding status

[Patrick Farrell]

Stepan,

In order to facilitate landing of the patches, EC is disabled by default even in that patch series.  If look in the tests, you can see the enablement process - it's two steps:
sudo lctl set_param llite.*.enable_erasure_coding=1
And:
export LFS_EC_OK=1
to allow setstripe

This is so we can land part of the feature without making it available before it is ready to use.  We will remove these gates at the 'end' of the development branch (we're not there yet!).

-Patrick
________________________________
From: Stepan Beskrovnyy <bsm099 at gmail.com>
Sent: Tuesday, January 27, 2026 6:47 AM
To: Patrick Farrell <pfarrell at ddn.com>
Cc: lustre-discuss at lists.lustre.org <lustre-discuss at lists.lustre.org>
Subject: Re: [lustre-discuss] File level erasure coding status

Hi! Thanks for the clue. I have builded and mounted actual lustre-ec branch. Tried to do 4+2 ec pattern for a file on a system and see this( see Picture).
Is this a bug? How can I avoid this ? Any suggestions ?
[image.png]
Thanks,
Stepan

On Thu, Jan 22, 2026 at 8:16 PM Patrick Farrell <pfarrell at ddn.com<mailto:pfarrell at ddn.com>> wrote:
Hi Stepan!

Erasure coding is very much an in-development feature.  There's some investigatory work going on by James Simmons at ORNL, and the main development effort is tracked here in JIRA:

https://jira.whamcloud.com/browse/LU-10911

The currently in-development code is here - this is the tip of a fairly long branch:
https://review.whamcloud.com/c/fs/lustre-release/+/62757

You can look at the tests in that branch for examples, but note the code is very much in active development.  There is a lot of churn and a number of known bugs.

But if you'd like to follow along, that's where the work is being done.  We'd also be happy to have feedback on the API if you're interested in taking a look.  (In the code - the API has changed some from what's documented in JIRA)

Thanks!
Patrick
________________________________
From: lustre-discuss <lustre-discuss-bounces at lists.lustre.org<mailto:lustre-discuss-bounces at lists.lustre.org>> on behalf of Stepan Beskrovnyy via lustre-discuss <lustre-discuss at lists.lustre.org<mailto:lustre-discuss at lists.lustre.org>>
Sent: Thursday, January 22, 2026 3:43 AM
To: lustre-discuss at lists.lustre.org<mailto:lustre-discuss at lists.lustre.org> <lustre-discuss at lists.lustre.org<mailto:lustre-discuss at lists.lustre.org>>
Subject: [lustre-discuss] File level erasure coding status

Hi everyone !

Is there any topics or threads with information about current lustre erasure coding development status and usage examples? If they exist, send links in reply to this message.

Thanks,
Stepan
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