Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Hi, below you can find some piece of information about my problem: > On Tue, Oct 13, 2009 at 11:54:54AM +0200, maurizio oggiano wrote: > > Hi all, > > I have a problem with a cluster degraded with a node inconsistent state. > > Is there a way to recovery a consistent state even if the sync source is dead? > > Maybe by means a snapshot, but I don't know how to do that. > > Can you elaborte on the situation? Yes. I have two nodes A e B syncronized. - A dies - B becomes primary and an application does some change on data managed by drbd - A reboots, so a syncronization starts from B to A. - the syncronization is interrupetd beacuse B dies. In this case I have a degraded cluster with a node with inconsistent data so It can't perform his functions > > Is this just a "what iff" question? yes. > --> we provide the before-sync-target and after-sync-target hooks. > if you use them as intended, you always have something consistent > to fall back to. In this case I want apply a strategy to recover a snapshot of a consistent data in order to guarantee ( even if a loss of data may happen) that degraded cluster works with consistent data. My question is the following : Is drbd is capable to take a snapshot of consistent data and use it in case of a degraded primary with inconsistent data? o maybe have I to write some script to use with before-sync-target and after-sync-target hooks? In this case if i take a snapshot when "before-sync-target" handler is activated can data managed by drbd change during the time I'm taking a snapshot? > > Are you already in a situation where your > only remaining copy of data had been sync target before? yes > Then you are in the unlucky situation, that your data is inconsistent. > Depending on how far the resync progressed before, and how desperate you > are in trying to reconstruct some of the content, > and of course, how much file system meta data blocks would have been > target of resync, you may be able to still get to most of the files, > in some state or other. But I'd probably rather go for the latest backup > than trying to do cumbersome forensics on a half-way bulk-updated file > system image. > > > Did I misunderstand the question? > Thanks Maurizio