Skipped groups in idmap2 on a cluster (with CTDB and GPFS)

Richard Sharpe realrichardsharpe at
Thu May 26 10:06:15 MDT 2011

On Thu, May 26, 2011 at 1:58 AM, Volker Lendecke
<Volker.Lendecke at> wrote:
> Hi, Richard!
> It should never happen that the idmap2.tdb is different on
> different nodes. That file is being covered by ctdb
> transactions, which are supposed to take care of making sure
> that they are the same everywhere. Can you say when this
> happened?

It happened on a customer site on 18-May-2011 or there abouts.

The customer was using robocopy to copy a share from a Win2k8 (I
think) node to the cluster.

There are two issues that I see:

1. The idmap2 files are different on the nodes on the cluster
2. The partial SID mapping info, but even worse is that it is the
GID-to-SID entry and it is partial as well.

There is a failed drive on one node which GPFS has kicked out and our
data is on a partition at the beginning of that drive, but it is
mirrored across four drives in the system, so MD should have taken
care of that and in any event, the failed drive is not on the node
that disagrees with the other two nodes.

I am investigating some more and will trawl through some more code.

What is vacuuming used for, BTW.

Richard Sharpe

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