Thursday, September 12, 2013

DBMT - It's how it shatters that matters

DBMT is a fantastic feature included with Domino 9 and you should be running it!

DBMT replaces the need to run Compact and Updall, it enables the ability to schedule multi-threaded maintenance such as Compact, Updall and Full Text Index over a configured time window.

The DBMT tool does all of the following:

    - Runs copy-style compact operations
    - Purges deletion stubs
    - Expires soft deleted entries
    - Updates views
    - Reorganizes folders
    - Merges full-text indexes
    - Updates unread lists
    - Ensures that critical views are created for failover

That's all great news, but there is a side-effect that comes with running DBMT that you may not be aware of - Fragmentation. To illustrate the effects we took a Domino 9 server and plotted fragmentation between scheduled invocations of the DBMT and plotted the results in the graph below:

This fragmentation WILL have a dramatic effect on overall server operations, Domino's I/O and also a very negative impact on backups. To help illustrate this impact, we have used IBM's testing and simulation tools to represent 200 users sending and receiving mail over a 7 hour period. We stopped the tests every hour and measured the results, which confirmed things can get rather bad, very quickly. What many people seem to forget is that your backup software must read the files off disk to back them up, the difference is real, not imagined. Please see the graph below.

We see this time and again when customers first come to us and put Defrag.NSF on their server and it pulls their files into shape, sometimes for the first time in years since the server was built, the results can't be ignored. There are servers out there in an absolute mess with literally hundreds of thousands of fragments and some admins are none the wiser for it because Domino will still function (slower), backups will still run (slower), web pages will still open (slower), and it will all seem very normal if that's your reference point and what you are used to working with every day!!

 The fact is, DBMT will get you to that point a LOT quicker, as shown in our DBMT fragmentation graph.

To avoid all this nastiness when utilising the benefits of DBMT you should also combine it with Defrag.NSF, so we have made it easy for you to run these tools together by integrating them into an easily configured one-stop UI. This feature provides an easy to use control interface and eliminates the requirement to use program documents to configure and run the tool. Once DBMT has completed it's maintenance, Defrag.NSF can be set to automatically run to clean up any fragmentation created by the DBMT tool.

Defrag.NSF's fully integrated solution allows you to easily configure your DBMT Compact, Updall and Defrag maintenance from one tab in Defrag.NSF. Nothing more to do! 

No comments: