On Wed, Jul 15, 2009 at 08:32:27AM -0400, Brian J. Murrell wrote: >On Wed, 2009-07-15 at 10:53 +0200, Tom Woezel wrote: >> Now the partition table on the raiddevice got deleted and >> cannot be recovered. >Ouch. How did it get deleted? How come it cannot be recovered? A >partition table is nothing more than a small area at the start of a disk >that contains pointers (i.e. offsets on the disk) to where partitions >start and end.
if a kernel is still up and looking at the device then /proc/partitions and /sys/block/<disk>/* might well still contain enough valid data from which the previous partition table can be reconstructed. been there, dd'd over that. (almost) all good in the end :-) thankfully not to a Lustre fs, just my home server :-/ cheers, robin -- Dr Robin Humble, HPC Systems Analyst, NCI National Facility >Even if it was completely wiped, the process of scanning the entire disk >looking for "signatures" that can help identify a likely partition >beginning and then recreate the partition table is usually quite >successful. You might want to look into the "gpart" tool for this. > >> The OSTs are ok and the data on those should be >> fine. > >Yes. But all you have is file "contents", nothing else. > >> Now here is my question is, it possible to create a new MGS and new >> MDTs and somehow connect the old OSTs to them? > >No. There is nothing on the OSTs that indicate what file an object >belongs to. This is why we are adamant about MDT storage being reliable >and backed up. > >> Is there a way to >> recreate the metadata with the data whis is held on the OSTs? > >No. > >> I'm deeply grateful for any help or hint on this issue. > >Without knowing the whole story of your MDT/RAID saga, I'd say gpart is >your best bet. > >b. > >_______________________________________________ >Lustre-discuss mailing list >[email protected] >http://lists.lustre.org/mailman/listinfo/lustre-discuss _______________________________________________ Lustre-discuss mailing list [email protected] http://lists.lustre.org/mailman/listinfo/lustre-discuss
