Your data is changing…

How much of your data is changing? This can be a difficult thing to estimate for any organization. Data Rate of Change is an important metric – without it, organizations would have no way of measuring how much bandwidth they will need to effectively protect and recover their production data.

For example, when referring to a 1TB database you may have a small rate of change, like 2% per day.  This may not seem like a lot, but it translates to about 20 GB of data – a large data increase that could require a dedicated 10 Mb link to move the data off-site daily.

Among Seagate small and medium business (SMB) clients, original data size varies greatly within and across user types.

AnnV_YourDataChanging1

 

 

 

 

Recovery Point Objective (RPO)

When estimating your Daily Rate of Change it is important to consider the Recovery Point Objectives (RPOs) determined by the needs of your lines-of-business. RPO periods define the number of times per day/week your data is replicated off-site.

If your organization’s primary database is 1 TB and your Daily Rate of Change is 2% per day, you will transfer approximately 20 GB of data in a single day. If the RPO for this database is set to 8 hours, replication will occur 3 times per day. You can assume that the average size of each transfer will be 2.5 GB. Thus, you should ensure that the current allotted bandwidth can support a 2.5 GB transfer within the 8 hour RPO.

AnnV_YourDataChanging2Daily Rate of Change Analysis

Among the population of Seagate SMB clients, we have seen the following patterns (see corresponding charts):

We can see that there is more variability in the amount of data being stored and replicated among Exchange users. The data also reveals that the average Exchange user, above the 75th percentile of Storage size, may require a dedicated link for data backups, depending on their RPO intervals.

Exchange jobs are significantly larger than those for SQL.  This is expected due to the nature of Exchange data being additions of new content every day, where SQL data can potentially be anything, but due to its strengths, tends to contain more updates than additions.  This helps show that if you will be protecting Exchange, it would likely benefit dis-proportionally more from increased bandwidth than would other types of servers.  Customers may want to consider a Satellite Appliance, augment bandwidth to these hosts, or potentially collocate the hosts at the Service Provider’s DC (Active/Primary Site).

Implications for Your Bandwidth

Daily Rate of Change is an important and telling indicator of your need for bandwidth. Checking your organization’s Daily Rate of Change in regular intervals can help ensure that you will always have enough bandwidth to move your data off-site in preparation for a disaster.

If your organization’s Data Rate of Change exceeds the amount of data that can be transferred on your existing bandwidth, within the required RPO – backup files will begin to queue and core data will not be managed off-site properly. In the event of a true disaster your data could be hours, days or weeks behind, thus missing the required RPO.

2015-01-22T14:45:12+00:00

About the Author: