Virtualization means DBA role conversion

"First, Oracle DBAs working on the x86 platform need to identify what benefits their organizations want to achieve through virtualization technology," said Tony Iams, senior operating system analyst and virtualization expert at Ideas International, New York Port Chester. --Database consolidation, higher availability, better load management or load balancing, or enhanced disaster recovery capabilities. Then, with these goals in mind, DBAs need to decide which database loads in their organization are appropriate for virtualization-and that's a tricky issue on the x86 platform.

"You have to be very careful because support for I/O virtualization is now the least mature on the x86 platform," Iams explained. "Both Intel and AMD have been trying to improve, and they are increasing support for virtualized I/O, but they are not yet complete, which will be in the next 18 months to 2 years." Before that, you have to be very careful, and the key is to understand how your database behaves over time. ”

Deciding what to Virtualize

Overall, the more intensive the database is, the higher the performance cost of virtualization will be, Iams said. As a result, he adds, DBA virtualization on the x86 platform is better for databases that are not frequently used, and there are many such databases.

"You may have some lightweight database services, these are not very urgent workloads, so if you want to make better use of your hardware, there is no reason why you should not use virtualization to merge these databases." "Iams said. "It just requires you to be more likely to understand the details of how these workloads behave over time." This means understanding the resources they need to represent with CPU, memory, and I/O, and really understand how urgent these applications are. Then you can make a clear decision as to whether it is suitable for virtualization. ”

But if the goal of DBAs is to use virtualization for database merging, remember that database consolidation is another thing, and it may be more prudent to merge with more traditional approaches-such as merging database tables into larger hosts-often cheaper and easier. Making decisions between virtualization and more traditional merge methods means weighing the performance costs and benefits of each approach, he said.

"If you want to merge databases, it would be wiser to simply merge the databases instead of merging the physical servers that are running on these databases," Iams said. "On the other hand, if you really want to make sure that these databases are completely isolated and that for some reason these databases are managed separately, it would be wiser to use virtualization." But again, you need to understand the performance costs of virtualization. ”

But what if it's on a UNIX platform?

In Unix systems, Iams explains that today's virtualization software is used to dynamically change the resources that are allocated to database fragmentation, which in many cases is very similar to virtual machines (dummy machine). The reason for this is that the organizational structure needs to be highly flexible in order to accommodate spikes in workloads that occur during a particular period of the year. For example, a big retailer could anticipate peak trading volumes during the Christmas period, he said.

"In Unix systems, there are some very advanced features to adjust the resources available online for each fragment without shutting down the database," Iams said. "Therefore, database administrators will be very familiar with workload management software or virtualization management software to develop policies to allocate resources on a constantly changing basis." This requires a DBA to spend a certain amount of cost. ”