y to applications on virtual machines by using VMware's Hypervisor software. Staff members need to monitor applications' memory usage SO that servers can be upgraded or applications moved to other hosts if memory in the current host is not adequate. If this isn't done, applications will run slowly and response times on individual user computers will be degraded. New servers are equipped with eight CPUs-quite literally, eight CPU chips on a single host server. However, as the amount of processing needed to run programs grows, even this is not always adequate for the virtual machines installed on them. Programs that have sound and video are "fatter," with more code, which requires additional CPU overhead. It's difficult to estimate under these conditions the amount of CPU power that's required for applications running on virtual machines. www.TechnicalPDF.com In addition, disk storage is being used up at a faster rate. Users now routinely store MP3 files in their e-mail inboxes. In data centers where user files and e-mail messages are archived, this can deplete spare storage in Storage Area Networks (SANs) at a faster rate than planned. Thus, storage, memory, and processing requirements should be monitored. In large, complex data centers, it can sometimes be easier to monitor and manage single physical servers rather than virtual machines and storage. In small organizations, managing memory, storage, and CPU usage is not as complex. With only three or four physical servers, it's not as difficult to track and manage resource allocation. Server Sprawl Server sprawl is the unchecked proliferation of virtual machines on physical host servers. (Virtual machines are also referred to as images.) Managing server sprawl in large data centers is a major challenge. Because it's easy to install multiple images of applications on virtualized servers, the number of applications can escalate rapidly. Data centers that previously had 1,000 servers with 1,000 applications can potentially now have 8 images per physical server and 8,