This step is available only if you chose to reuse existing Linux partitions. partitionsformattingIf you chose to reuse some legacy GNU/Linux partitions, you may wish to reformat some of them and erase any data they contain. To do so, please select those partitions as well. Please note that it's not necessary to reformat all partitionspre-existing pre-existing partitions. You must reformat the partitions containing the operating system (such as /, /usr or /var) but not the partitions containing data you wish to keep (typically /home). Please be careful when selecting partitions. After the formatting is completed, all data on the selected partitions will be deleted and you won't be able to recover it. Click on Next when you're ready to format the partitions. Click on Previous if you want to choose other partitions for your new Mageia operating system installation. Click on Advanced if you wish to select partitions which will be checked for partitionsbad blocksbad blocks on the disk.