User guide

ASUSTOR NAS User Guide
Page 18 of 52
at all times. RAID 1 protects your data from loss should one of your disks
fail. RAID 1’s advantage is that it offers protection for your data by providing
data redundancy. The downside of this configuration is that when combining
two disks of differing sizes, the total storage space will be equal to the size
of the smaller disk. Therefore, you will be unable to use a portion of the
larger disk.
Total available storage space = (size of smaller disk) * (1)
 RAID 5: Combines three or more disks to create a storage space that is able
to support one failed disk. Should one of your disks fail, your data will still
be protected from loss. In the event of disk failure, simply replace the failed
disk with a new one. The new disk will automatically be accommodated into
the RAID 5 configuration. The advantage of using RAID 5 is that is that it
provides data protection through data redundancy. The downside to using
RAID 5 is that when combining disks of differing sizes, the total storage
space will be calculated based on the size of the smallest disk.
Total available storage space = (size of smallest disk) * (total number of
disks – 1)
 RAID 6: Combines four of more disks to create a storage space that is able
to support two failed disks. Should two of your disks fail, your data will still
be protected from loss. In the event of disk failure, simply replace the failed
disks with new ones. The new disks will automatically be accommodated into
the RAID 6 configuration. The advantage of using RAID 6 is that it is able to
provide superior data protection through data redundancy. The downside to
using RAID 6 is that when combining disks of differing sizes, the total
storage space will be calculated based on the size of the smallest disk.
Total available storage space = (size of smallest disk) * (total number of
disks – 2)
 RAID 10 (1+0): Combines four or more disk to create a storage space that
is able to support multiple failed disks (as long as the failed disks do not
belong to the same “mirrored set”). RAID 10 provides the data protection of
RAID 1 along with the access efficiency of RAID 0. With respect to data
protection, RAID 10 uses the RAID 1 method of having the exact same data
written identically on two disks, producing “mirrored sets”. These “mirrored
sets” are then combined together in a RAID 0 configuration. RAID 10
requires an even number of four or more disks. When combining disks of
differing sizes, the total storage space will be calculated based on the size of
the smallest disk.
Total available storage space = (size of smallest disk) * (total number of
disks / 2)
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NAS 251 – Introduction to RAID