Does slapcat support large file?

There is more than 250,000,000 entries in my openldap's id2entry.dbb, and the data file's size is larger than 9 G.

I want to dump all the entry to ldif file using slapcat (/usr/local/sbin/slapcat ),but slapcat exited only dumped 970,000,000 entries.

what can i do to get all the data in my id2entry.dbb?

OS: linux RH 7.2 or RH advance server 2.1

openldap: 2.0.8

berkely db: 3.19

Thans fro help !

james