<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Thank you all for the answers so far. The main problem with the raid is that the partition table has been overwritten. I don't know how it happened but it seems that another machine could see the raid device during a kickstart installation and used it (some of our kickstart files use the clearpart --all --initlabel option).<div><br></div><div>However I was able to recover a partition table with gpart (tried TestDisk befor and didn't work) and will now see if I can somehow recover the MGS and MDTs.</div><div><br></div><div>Regards</div><div>Tom</div><div><br><div><div>Am 15.07.2009 um 15:53 schrieb Andreas Dilger:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div>On Jul 15, 2009 08:32 -0400, Brian J. Murrell wrote:<br><blockquote type="cite">Even if it was completely wiped, the process of scanning the entire disk<br></blockquote><blockquote type="cite">looking for "signatures" that can help identify a likely partition<br></blockquote><blockquote type="cite">beginning and then recreate the partition table is usually quite<br></blockquote><blockquote type="cite">successful. You might want to look into the "gpart" tool for this.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">On Wed, 2009-07-15 at 10:53 +0200, Tom Woezel wrote:<br></blockquote><blockquote type="cite"><blockquote type="cite">Now here is my question is, it possible to create a new MGS and new <br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">MDTs and somehow connect the old OSTs to them?<br></blockquote></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">No. There is nothing on the OSTs that indicate what file an object<br></blockquote><blockquote type="cite">belongs to. This is why we are adamant about MDT storage being reliable<br></blockquote><blockquote type="cite">and backed up.<br></blockquote><br>That isn't totally correct - there is an xattr on each OST object that<br>contains the MDT inode number and stripe index for that object. That<br>doesn't help much in this case, because you will still have a whole<br>filesystem of objects without filenames.<br><br><blockquote type="cite">Without knowing the whole story of your MDT/RAID saga, I'd say gpart is<br></blockquote><blockquote type="cite">your best bet.<br></blockquote><br>Recovering the MDS data using gpart seems like a better idea. If the<br>corruption is in the RAID layout itself, that is a harder issue to fix.<br><br>Cheers, Andreas<br>--<br>Andreas Dilger<br>Sr. Staff Engineer, Lustre Group<br>Sun Microsystems of Canada, Inc.<br><br>_______________________________________________<br>Lustre-discuss mailing list<br><a href="mailto:Lustre-discuss@lists.lustre.org">Lustre-discuss@lists.lustre.org</a><br>http://lists.lustre.org/mailman/listinfo/lustre-discuss<br></div></blockquote></div><br><div> <span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><span class="Apple-style-span" style="font-family: 'Nimbus Sans L'; font-size: 9px; "><pre class="moz-signature" cols="72">-----------------------------------------------------------------
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