<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><br></div><div>We are about to upgrade our standalone MGS/MDS (no failover) from 1.6.4.2 to 1.8.0.1. I'm a little confused by section 13.2.4 of the Lustre 1.8 Operations Manual. What is the purpose of the </div><div><br></div><div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 9px/normal Courier; "><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px;">mdt1# tunefs.lustre --mgs --mdt --fsname=testfs /dev/sda1</span></font><span style="font: 12.0px Helvetica"> </span></div><div><br></div><div>command? I assume it is writing this information to the MDT (/dev/sda1) but wan't that information alright put there when the file system was created under 1.6.4.2? Has the format changed between the two versions? Why is the tunefs.lustre step necessary? I'm concerned about overwriting *anything* on the MDT and rendering our file system unusable. I just want to be sure we understand what we are doing.</div><div><br></div><div>The paragraph labeled "Description" in section 32.2 (describing tunefs.lustre) did not exactly give me a warm-fuzzy. </div><div><br></div><div>BTW, we already have a number of 1.8.0.1 clients running against the 1.6.4.2 servers. Working great so far!</div><div><br></div><div>Thanks,</div><div><br></div><div>Charlie Taylor</div><div>UF HPC Center</div></div></body></html>