Create a software RAID5 with mdadm
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Create your partitions on your disks, don't format the partitions
mdadm --create /dev/md0 --level=5 --assume-clean --raid-devices=4 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1
Create your partitions on your disks, don't format the partitions
mdadm --create /dev/md0 --level=5 --assume-clean --raid-devices=4 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1