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

Richard Sharpe realrichardsharpe at
Wed May 25 15:58:32 MDT 2011

On Tue, May 24, 2011 at 1:42 PM, Richard Sharpe
<realrichardsharpe at> wrote:
> Hi,
> Has anyone seen cases where group numbers have been skipped (ie, not allocated).
> We are allocating numbers up in the range 16777216 and up.
> I am investigating a problem and I find that the output from wbinfo -G
> from 16777309 to 16777320 shows a gap of unallocated GIDs from
> 16777310 to 16777313.
> However, there is a file/dir that was created via Samba that has the
> GID 16777312 in its ACL.
> Any suggestions on what has happened?

Further on this, if I do tdbdump on two nodes in the cluster and grep
for 16777312, I see:

tdbdump /ctdb/persistent/idmap2.tdb.1 | grep 16777312
key(13) = "GID 16777312\00"
key(13) = "UID 16777312\00"
data(37) = "\01\00\00\00\00\00\00\00\01\00\00\00\02\00\00\00\00\00\00\00\00\00\00\00UID

and on one node I see:

tdbdump idmap2.tdb.2 | grep 16777312
key(13) = "UID 16777312\00"
data(37) = "\01\00\00\00\00\00\00\00\01\00\00\00\02\00\00\00\00\00\00\00\00\00\00\00UID

Thus it would appear that there is a problem in that two nodes have a
key for GID 16777312 but no data.

Is this normal?

Richard Sharpe

More information about the samba-technical mailing list