Ok, so you want to have an idea how large your Operations Manager databases are going to be. And you want it to be a little more exact than “larger than a gigabyte, smaller than a terabyte.” We have been working on this question for a while now and have developed the following methodology that provides high-level estimates for database sizing for the three databases in OpsMgr: Operations DB, Data Warehouse DB, and ACS DB.
First, the caveats. These are estimates based upon our testing results and may not take into considerations specific aspects of your environment such as large numbers of management packs, customized management packs, extremely chatty management packs,or other factors which may impact your database size. With that said however, this is how we came up with our numbers.
OpsDB: We installed a new version of each database and determined what amount of space was used when it had been installed but prior to when agents began reporting data. (This means it had configuration data with minimal operational data.) We monitored what tables were increasing to validate that it was directly related to both the retention period of the data being held and the number of agents providing information. From these we were able to determine an approximate impact on a per-agent basis to the database size, which was 5 MB/day. We added an approximately 40% contingency factor to come up with the estimated sizing. The following is the resulting formula:
(5 MB/day x Number of Agents x Retention Days) + 510 MB = Operations Manager Database Estimate
|Grooming Interval (days)||3000 Agents||2000 Agents||1000 Agents||500 Agents||
|50 Agents||10 Agents|
Data Warehouse DB: This was done using the same concept as the OpsDb with a similar level of contingency. The following is the resulting formula:
(3 MB/day x Number of Agents x Retention Days) + 570 MB = Data Warehouse size estimate
|Retention Period||3000 Agents||2000 Agents||1000 Agents||500 Agents||
|50 Agents||10 Agents|
ACS DB: This one was more complex due to the factors involved with different types of systems reporting to ACS (workstations, servers, domain controllers). To factor in these differences we put an approximate weight to each of these (1 to a workstation, 5 to a server, 100 to a domain controller). The following is the resulting formula:
(8 MB/day x (Number of Workstations) x Retention Days) +
(8 MB/day x (Number of Servers * 5) x Retention Days) +
(8 MB/day x (Number of Domain Controllers * 100) x Retention Days) + 8 MB = ACS Database Size Estimate
|Grooming Interval (days)||3000 WS, 600 Server, 14 DC||2000 WS, 400 Server, 10 DC||1000 WS, 200 Server, 8 DC||500 WS, 100 Server, 5 DC||
100 WS, 20 Server, 2 DC
|50 WS, 10 Server, 2 DC||10 WS, 2 Server, 1 DC|
From what we have seen so far, these equations match well with results we have seen published. Hopefully, this will help you provide more accurate estimates of the database storage sizes required for OpsMgr 2007.