[Lustre-discuss] mixing server versions

[Bernd Schubert]

On Wednesday, September 15, 2010, Andreas Dilger wrote:
> On 2010-09-15, at 13:32, Brock Palen wrote:
> > Thanks that is great to know.  Is there much risk to try with 1.8 and
> > then back off to 1.6 if there are issues?  Risk of data loss?
> 
> We do not test/support formatting at a higher Lustre version, and then
> downgrading below the original version used for formatting.  With 1.6->1.4
> this definitely did not work, though I'm not sure if there are specific
> incompatibilities between 1.8->1.6.

I go back and forth from 1.8 to 1.6 quite often. The only thing to take care 
about is to make sure the MDS does not get the extents flag if ext4-ldiskfs is 
used. I think only beginning with 1.8.4 that is ensured by Lustre itself.

Cheers,
Bernd

-- 
Bernd Schubert
DataDirect Networks