[LU-4665] utils: lfs setstripe to specify OSTs

• Status: Resolved
• Project: Lustre
• Fix Version/s: Lustre 2.7.0
• Type: New Feature
• Priority: Critical
• Reporter: Jinshan Xiong (Inactive)
• Assignee: Emoly Liu
• Resolution: Fixed
• Labels: llnl
• Severity: 3

Description

#5: Sparse OST indicies
#6: Setstripe for specified OSTs.

Issue Links

• is related to: LU-3840 llapi_layout API design discussion
• is related to: LU-6135 improved support for selecting specif...
• is related to: LU-5170 lfs usability
• is related to: LU-5878 lfs migrate sends file to stdout
• is related to: LU-8417 setstripe -o does not work on directo...
• is related to: LU-9392 lfs migrate -o and lfs setstripe -o s...

Comments

[Jinshan Xiong (Inactive)]

patch is at: http://review.whamcloud.com/#/c/9383

[James A Simmons]

People have at ORNL have been asking for #6 for a very long time. You made many people happy.

[Christopher Morrone]

Ditto. LLNL folks have been asking for that a long time as well.

[Jian Yu]

Patch to improve Lustre test framework to support specifying arbitrary OST indices: http://review.whamcloud.com/9722
Patch to add regression test cases into conf-sanity.sh: http://review.whamcloud.com/9775

[James A Simmons]

I like to suggest that we rebase this work on top of LU-2182. The LU-2182 work is in pretty good shape.

[Christopher Morrone]

I agree with James.

[James A Simmons]

If you don't have the time Jinshan I will gladly do the work.

[Jinshan Xiong (Inactive)]

Hi James,

Please feel free to pick it up and move it forward. Thanks

Jinshan

[Shuichi Ihara (Inactive)]

Is this still for regular file only? What's other porject or dependency to support specific OST selection for directory?

[James A Simmons]

Started integrating this work with LU-2182.

[Jinshan Xiong (Inactive)]

Hi James,

Are you still working on this? We're going to land this patch in 2.7.

[James A Simmons]

Yes. In fact I'm debugging it right now.

[Jinshan Xiong (Inactive)]

Is there any problems with the patch?

[James A Simmons]

Not with the patch directly. I did see failures due to the new layout api using fsetxattr instead of the ioctl for setting stripes. There was code in ll_setxattr that if sent in stripe_offset was set to zero it was set to -1 which meant a random OST was picked instead of OST 0. The base LU-2182 patch which this work depends on should now behave properly. We will see once Maloo is done.

[Peter Jones]

Emoly

Could you please assist with reviewing these patches?

Thanks

Peter

[Oleg Drokin]

This feature totally needs a way to specify ost_count in addition to OST list that way we do not force user to do their own load balancing.
Say I have a set of 100 OSTs that are local enough for my set of nodes, but I only need a striping of 4...
We seriously should consider adding this as a follow on patch.

[Oleg Drokin]

Ah, I also noticed that the current patch returns error if ldo_def_stripe_offset is not in the list of OSTs, but failed to consider that -1 should mean "use something that makes sense". This too needs to be addressed. Esp. in light of the previous comment

[Andreas Dilger]

Is it possible to access this functionality via the new llapi_layout_* API added in LU-3840? It doesn't seem like it looking at the code. I've got a partially completed patch to add this, will link it here when I push the patch.

[James A Simmons]

No. The llapi_layout api is not mature enough to be used. I tried using it as a back end but it just broke lots of test.

[Andreas Dilger]

I've pushed http://review.whamcloud.com/12663 but it is a best-effort patch for now. It doesn't have a test case yet, and has had no testing at all.

[Andreas Dilger]

Emoly, could you please refresh the 12663 patch according to the review comments, and add a test case for this to the llapi_layout_ test program.

[Emoly Liu]

Andreas, sure.

[Jinshan Xiong (Inactive)]

Do we need a new ticket # for http://review.whamcloud.com/#/c/12275?

[Andreas Dilger]

I opened LU-6135 for the follow-on patches.

[Andreas Dilger]

Have moved the other patches over to LU-6135.