So after updating our dev ldap environment to use mdb, and slapadd'ing a fresh copy from our production environment into it, the database was using 828M: Environment Info Map address: (nil) Map size: 2147483648 Page size: 4096 Max pages: 524288 Number of pages used: 211612 Last transaction ID: 1333 Max readers: 126 Number of readers used: 6 Status of Main DB Tree depth: 1 Branch pages: 0 Leaf pages: 1 Overflow pages: 0 Entries: 29 I then proceeded to run a test load on it (basically, I had a script I put together when I added the memberof overlay that ripped through all of our groups, removing and then re-adding all members). After this test run, the use jumped to 1.9G: Environment Info Map address: (nil) Map size: 2147483648 Page size: 4096 Max pages: 524288 Number of pages used: 479536 Last transaction ID: 1075380 Max readers: 126 Number of readers used: 11 Status of Main DB Tree depth: 1 Branch pages: 0 Leaf pages: 1 Overflow pages: 0 Entries: 29 There is no new data in the database, all that happened was existing data was removed and then re-added. Is this drastic increase in space utilization expected in such a scenario? I bumped the max size from 2G to 4G and am rerunning the same script to see what happens. Is there any heuristic for how mdb will grow over time, based on the initial size from a fresh slapadd? I plan to set a fairly large maxsize, and also monitor it with munin to keep track of any unexpected growth, but I am curious if it is going to reach a steady-state size or continue growing over time. I would expect growth as additional entries were added, and possibly some growth from overhead when things were changed, but not necessarily such a big jump in size. Thanks.