[lustre-discuss] oldest lustre deployment?

[Andreas Dilger]

On Aug 15, 2018, at 08:40, Latham, Robert J. <robl at mcs.anl.gov> wrote:
> 
> I am looking at the patch to ROMIO to support the new Progressive File
> Layout feature:
> 
> https://jira.whamcloud.com/browse/LU-9657
> and
> https://review.whamcloud.com/#/c/27869/10
> 
> This change greatly reworks ROIMIO's support for determining striping count and stripe size.  I'm all for using the 'llapi_layout' routines instead of bare ioctl() calls, but llapi_layout did not show up until 2.7 I think.
> 
> Is there any chance that some enviroment out there is still running a
> lustre from 2014 or earlier?
> 
> Nothing before 2.10 shows up in the "community matrix"
> 
> https://wiki.whamcloud.com/display/PUB/Lustre+Support+Matrix

There is also the separate question of whether anyone running an ancient
version of Lustre (which also requires an ancient kernel) will be updating
their MPICH to the latest version?

In any case, it appears that the MPICH demands on llapi_layout_*() are
fairly small, and it should be straight forward to implement stubs for the
few functions that it is using (which are for non-PFL files).  If such
an MPICH library is run against a newer version of Lustre, it will return
some approximate values via the old interface, which may not be ideal but
are no worse than runnnig an older MPICH library.

Cheers, Andreas
---
Andreas Dilger
Principal Lustre Architect
Whamcloud







-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 235 bytes
Desc: Message signed with OpenPGP
URL: <http://lists.lustre.org/pipermail/lustre-discuss-lustre.org/attachments/20180816/151bef2c/attachment.sig>