Table
RAID Level | Main Characteristics | Advantages |
RAID 1 (mirroring) | Mirrors data on one physical |
| disk to another, to provide |
| basic redundancy. |
| In the event of a single |
| physical disk failure a second |
| copy of the data exists, which |
| can be used to restore the |
| data to a new, replacement |
| physical disk. |
Useful when only two physical disks are available, and when data integrity is more important than storage capacity.
RAID 10 (striped | Combines mirrored and |
mirror sets) | striped sets; data are striped |
| across mirrored sets of |
| physical disks. |
| RAID 10 allows multiple |
| physical disk failures, up to |
| one failed physical disk in |
| each mirror that has been |
| striped. |
| In the event of a single |
| physical disk failure (per |
| mirror set) a second copy of |
| the data exists, which can be |
| used to restore the data to a |
| new, replacement physical |
| disk. |
•Offers better performance than a simple mirror because of the additional physical disks.
•Requires twice the disk space of RAID 0 to offer redundancy.
•When a physical disk in a RAID 10 virtual disk fails, the virtual disk is still functional. Data is read from the surviving mirrored disk.
Appendix B
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