High availability using virtualization - 3RC

High availability has always been one of the main problems for a data center. Till now high availability was achieved by host per host redundancy, a highly expensive method in terms of hardware and human costs. A new approach to the problem can be offered by virtualization. Using virtualization, it is possible to achieve a redundancy system for all the services running on a data center. This new approach to high availability allows the running virtual machines to be distributed over a small number of servers, by exploiting the features of the virtualization layer: start, stop and move virtual machines between physical hosts. The 3RC system is based on a finite state machine, providing the possibility to restart each virtual machine over any physical host, or reinstall it from scratch. A complete infrastructure has been developed to install operating system and middleware in a few minutes. To virtualize the main servers of a data center, a new procedure has been developed to migrate physical to virtual hosts. The whole Grid data center SNS-PISA is running at the moment in virtual environment under the high availability system.Comment: 10 page

Plasma retinol and tocopherol levels in relation to demographic, lifestyle and nutritional factors of plant origin in Greece

In the context of the Greek segment of the European Prospective Investigation into Cancer and Nutrition (EPIC) we have conducted a cross-sectional study to determine the effect of demographic, lifestyle and nutritional factors of plant origin on retinol, α-tocopherol and γ-tocopherol. Study subjects were a random sample of forty-five men and sixty-eight women, aged 30-82 years, from the Greek EPIC cohort of 27953 volunteers. Analyses were done using linear regression models with the vitamin blood levels as dependent variables, and BMI, the intake of selected food items, total energy intake and a set of demographic factors as independent variables. Women had significantly lower plasma retinol levels (P<0.006) than men. Both α- and γ-tocopherol levels increased by approximately 5% for every additional 5 years of age. Among dietary factors, intake of non-fruity vegetables was associated with increase, while intake of added lipids other than olive oil with decrease, of plasma retinol levels. BMI was positively associated with plasma γ-tocopherol only, while none of the foods or food groups investigated significantly affected the plasma levels of either of the two tocopherols. These findings need to be confirmed before attempts are made to use them in the context of explanatory mechanistic processes