gpfsug-discuss-boun...@spectrumscale.org wrote on 07/27/2017 05:09:31 PM: > From: Jonathan Buzzard <jonathan.buzz...@strath.ac.uk> > To: gpfsug main discussion list <gpfsug-discuss@spectrumscale.org> > Date: 07/27/2017 05:09 PM > Subject: Re: [gpfsug-discuss] Lost disks > Sent by: gpfsug-discuss-boun...@spectrumscale.org
> > On Thu, 2017-07-27 at 16:18 +0200, Uwe Falke wrote: > > > "Just doing something" makes things worse usually. Whether a 3rd > > party tool knows how to handle GPFS NSDs can be doubted (as long as it > > is not dedicated to that purpose). > > It might usually, but IBM have *ALREADY* given up in this case and told > the customer their data is toast. Under these circumstances other than > wasting time that could have been spent profitably on a restore it is > *IMPOSSIBLE* to make the situation worse. SCNR: It is always possible to make things worse. However, of course, if the efforts to do research on that system appear too expensive compared to the possible gain, then it is wise to give up and restore data from backup to a new file system. > > [SNIP] > > > It seems not a bad idea to set aside the NSD headers of your NSDs in a > > back up :-) > > And also now: Before amending any blocks on your disks, save them! > > > > It's called NSD v2 descriptor format, so rather than use raw disks they > are in a GPT partition, and for good measure a backup copy is stored at > the end of the disk too. > > Personally if I had any v1 NSD's in a file system I would have a plan > for a series of mmdeldisk/mmcrnsd/mmadddisk to get them all to v2 sooner > rather than later. Yep, but I suppose the gone NSDs were v1. Then, there might be some restrictions blocking the move from NSDv1 to NSDv2 (old FS level still req.ed, or just the hugeness of a file system). And you never know, if some tool runs wild due to logical failures it overwrites all GPT copies on a disk and you're lost again (but of course NSDv2 has been a tremendous step ahead). Mit freundlichen Grüßen / Kind regards Dr. Uwe Falke IT Specialist High Performance Computing Services / Integrated Technology Services / Data Center Services ------------------------------------------------------------------------------------------------------------------------------------------- IBM Deutschland Rathausstr. 09111 Chemnitz Phone: +49 371 6978 2165 Mobile: +49 175 575 2877 E-Mail: uwefa...@de.ibm.com ------------------------------------------------------------------------------------------------------------------------------------------- IBM Deutschland Business & Technology Services GmbH / Geschäftsführung: Andreas Hasse, Thomas Wolter Sitz der Gesellschaft: Ehningen / Registergericht: Amtsgericht Stuttgart, HRB 17122 _______________________________________________ gpfsug-discuss mailing list gpfsug-discuss at spectrumscale.org http://gpfsug.org/mailman/listinfo/gpfsug-discuss
