today a customer asked for a server to be configured at RAID 0+1

what what the heck is raid 0+1?

im familiar with raid 0 and raid 1, but never heard of raid 0+1

so im going to try to explain to you what it is

RAID 0 + 1 provides disk stripping with mirroring. it merges the features provided by RAID 0 and RAID 1. data is mirrored between two sets of disk stripes. it provies complete redundancy and enables you to sue four or more disks as a set. this is also called fault tolerance. see the image/picture