NOTE : The model here only applies to a single, non-clustered CQ instance, with default, out-of-the-box configuration. You are advised to build enough of a buffer for variations when sizing an entire system with multiple “author” and “publish” instances, and DEV, QA, STAGING and PROD environments.

The “Data Store” is a part of CQ’s JCR (Java Content Repository) that stores “large” binary data. It is physically located at \crx-quickstart\repository\repository\datastore\ but can be configured to be hosted on a separate disk array. “Large” is a configurable parameter, default is 4 KB.

To model the disk storage requirements for the Data Store, I conducted 5 tests whereby for each test I loaded CQ DAM with 10,000 unique 1680 x 1050 1 MB JPG images. Essentially, each test loaded CQ with 10 GB of data. By the last test, CQ had 50,000 images constituting 50 GB of data.

Regression analysis using Microsoft Excel yielded a model that can roughly predict the required disk storage for the Data Store with the following equation (where y = Data Store disk storage and x is the image data size):

y = 1.87x + 0.36

In other words, storing image data in the JCR Data Store incurs a storage overhead of about 1.87x. Therefore, for 30 GB of image data, you should provision about 1.87 x 30 = 56 GB of storage. Please note that only Data Store storage is considered here, not the entire repository.

See chart below (linear regression analysis):