Upgrading should be OK, but it is not currently possible to downgrade to 2.6 (or earlier versions). See LU-6050 for details: https://jira.hpdd.intel.com/browse/LU-6050

Depending on what you do while the system is upgraded, you may be able to downgrade, but any files created while 2.6.90 was running will have permissions issues, and it's possible to get in a situation where you can't write to the file system after downgrade.

- Patrick

On 01/06/2015 03:17 AM, Jérôme BECOT wrote:

Hello,

Can someone here confirm if i'm safe from any risk of data corruption or any further troubles by upgrading my MDS and OSS servers software from the online feature release 2.6.0-RC2--PRISTINE-2.6.32-431.20.3.el6_lustre.x86_64 to the last 2.6.91 version ? or is there some modifications that may lead to a possible crash ?

(proceeding to the usual stop-start services respecting the good order)

We are running test over our new platform here that lasts for more consequent purposes and as the 2.7 will be out there shortly we want to keep it functionnal in 2.6.

Thanks