On Tue, 2009-01-06 at 17:15 +0000, Bryn M. Reeves wrote: > SoulSweeper wrote: > > On Tue, 2009-01-06 at 12:08 +0000, Bryn M. Reeves wrote: > >> Ralf Sparr wrote: > >>> Hi list, > >>> > >>> as mentioned in my earlier post, LVM complains about > >>> "Incorrect metadata area header checksum". As this occurs > >>> often (many questions, rarely answers in the list) I tried to create > >>> some 'new' via > >> Running pvcreate followed by vgcfgrestore is the correct way to fix a > >> broken MDA checksum - I've used this many times to recover from these > >> situations. > > > > Hmmm, doesn\t sound very promising. Why does this happen? The error > > directly occured after shutting the lvm down. I wanted to reboot the > > server to check a new network-configuration (no LVM changes at all). > > loop-aes & md were still up. > > It's hard to say - when I've encountered this in the past, I've usually > been doing things that I'd expect might introduce a bit of "excitement" > to the system, e.g. reproducing bugs that involve crashing the kernel > with a lot of I/O happening. > > I am not aware of any deterministic steps that would trigger this under > normal circumstances (and I'd consider it a bug if I was :) - when I've > needed to demonstrate how to recover from this in the past I've had to > resort to writing code to deliberately trash the checksums. > > You mention that you're using loop-aes and md, I wonder if maybe > something's being cached or not flushed to disk correctly when you > reboot that could be causing corruption? Very unlikely. The system itself is located on a mirror. loop-aes is on my 'data-raid', then lvm is accessing the loop-device. LVM hosts my xen-domu's and data-partitions. I run shutdown on every domU and did a 'vgchange -a y'. Then the error became visible. LVM doesn't shutdown, access to the LVs were still posible. Then the server was rebooted, but this time without any accessible LV. After all, I don't really care about the 'why'. My data is back online! Again, many thanks to you. rgds Ralf > > Regards, > Bryn. > > > _______________________________________________ > linux-lvm mailing list > linux-lvm@redhat.com > https://www.redhat.com/mailman/listinfo/linux-lvm > read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/ _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
