On Wed, Aug 08, 2007 at 03:03:38PM -0400, Stuart D. Gathman wrote: > That's good. But I've been lurking and noticed that when things > go disastrously wrong, and some poor admin posts here hoping for a miracle, > the key to the miracle is having a copy of the LVM metadata somewhere for > use with vgcfgrestore. Apparently, the PV copies are not enough for > current tools to allow recovery from some situations. No distribution that I'm aware of uses the existing facilities in full to solve problems at system boot. If things aren't exactly right they fail and leave the user to work out how to clean up the mess. There's quite a bit of logic that could be added to the initrd/initscripts to handle - or at least report on - certain failure situations using the existing LVM2 features. Secondly, by the time admins seek help, they've sometimes already made their situation many times worse by attempting to fix things the wrong way. Worse, they sometimes realise they did something stupid and convince themselves they can still get sensible advice without revealing everything they know they did. So someone providing that help needs to try to check everything in more than one way in case relevant information is being withheld. Mechanisms to help skilled support engineers deal with such situations efficiently pervade the LVM2 design. The lvm_dump.sh script is being developed to capture the essential information about an LVM2 system, and eventually we hope to have tools to analyse and report upon the contents of the dump. 'pvck' is also under development to aid recovery from one class of problems. > Certainly, automatically bringing all remaining LVs online after > PV failure is a must. That's an example in point. The LVM2 tools have offered facilities to do that for several years. The distributions do not yet make use of them. Alasdair -- agk@redhat.com _______________________________________________ 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/
