OM12 Installation Quick Trick 01: OM12 Database Sizes & When To Set Them

In a series of postings I will share some quick tricks for installing OM12. This is the first posting in this series.

When installing OM12 one needs to enter the sizes required for both OM12 databases. Of course, you have done your homework and calculated the required sizes for both OM12 databases using the OM12 Sizing Helper Tool (this file is way down the list):

However, the question is WHEN do you set the sizes of those databases? My advice is not to set them during the installation, as shown in these two screenshots for the OperationsManager and OperationsManagerDW databases:

But leave those sizes at their defaults (1000 MB) during the installation. Why?

Already in the days of SCOM (R2) I noticed when I changes the size of those databases during the installation, it could take a really long time for setup to finish. Which isn’t a good thing since the installation is a basic thing to be performed and the time saved during that phase can be used in a better way, like configuring SCOM R2.

With OM12 the same thing is still happening. When changing the sizes of the databases to their proper values during the installation, it takes a long time to create those databases. Therefore I always use this approach:

Calculate the required size of your OM12 databases on the amount of servers, network objects and APM enabled devices;

Use the result of that calculation for your OM12 databases sizing;

Install OM12 and both databases using the default values as presented by the installer (1000 MB for both databases);

When the whole OM12 infrastructure is installed (OM12 Management Servers, OM12 databases and OM12 Reporting) modify the size of the OM12 databases using SQL Server Management Studio.

Open the properties of the OperationsManager database > Files and changes the size of the MOM_DATA file to the correct size in MBs.

Click OK and after a while the size is modified.

Repeat Step 5 and 6 for the OperationsManagerDW database.

In the next posting I’ll tell you more about the owner of the OM12 databases which is easily overlooked but needs some attention as well.