There are three factors that may influence your choice of RAID level: usability (redundant data), performance and cost. If you do not need usability, RAID-0 can perform best. If usability and performance are more important than cost, RAID-1 or RAID-10(it depends on the number of disks) is a good choice. If price is as important as usability and performance, you can choose RAID-3，RAID-30，RAID-5 or RAID-50(it depends on the transmission type and the number of disk drivers)
Strengths of RAID: Low cost，little power consumption，high transmission speed。 Fault-tolerance function Data security
RAID applies for: E-Mail server Workgroup/file server Corporation server Storage LAN Internet news server ……
Nowadays, RAID is a quite good storage technique. It has advantages in storage capacity, storage security and storage speed. However, once there are some failures in RAID, the loss is ususally tremendous.
Situations in which RAID information may lose:
The RAID array card breaks down
Physical failures of disk
Extracting disk in wrong order
Reallocation RAID array information
Disk electric line falls off
High temperature of node caused by heat dissipation
Some methods for above questions
Not easily attempt rebuild, synchronization etc.
Analyze mirror file, reconstruct data
Creat RAID information, analyze the construction of data
Some problem can be solved by software, such as RAID Reconstrustor，R－Studio Data Recovery Wizard Professional 3.0 etc. These software can help recreate Raid information, analyze disk order, reconstruct array information, finally restoring Raid disk.