Hi, all. After running for a good long time with Lustre 1.8.4 everywhere on SL5 we are in the process of upgrading everywhere to SL6.4. We plan on taking down our entire Lustre system at once, then bringing it back up under SL6.4/Lustre 2.1.6. The process as documented in Chapter 16 of the user's guide looks pretty straight forward. Are there any "gotchas" I should know about? We are not planning on reformatting any file systems. Thanks, bob PS, apologies to whom it may concern that I originally sent this to hpdd-discuss-request