Thursday, September 3, 2015

Domino Fragmentation Analyzer's first major find - 13,954,029 Fragments on a single server

We just got the following report in from a server (9.0.1 FP 3) with 2000 users on it. Lots of data, and long backup times.

It's a mess, with nearly 14 million fragments (one NSF file has over 173 thousand).

The good news is, here we have an opportunity to improve performance in a huge way!

They didn't know... and now they do.. check to see what DFA might be able to tell you!


Dovid said...

Is DBMT being run against the applications on the server?

Adam Osborne said...


No it wasn't (just like most Domino Servers we've seen). We kicked it off to see what it could do (after all there was a massive amount of freespace), and the results were still very very poor - one file still had over 51,000 fragments.

Once freespace is fragmented the pre-allocation function in DBMT has limited value. We've blogged about this before.

The Pre-allocation function was introduced to address concerns we raised back when DBMT became available, John Paganetti of IBM used our research in his presentation at Connect 2014.

Adam Osborne said...

After more testing, it appears that once freespace get out of shape, DBMT pre-allocation now longer works very well at all.