Dell
DELL PERC H700 and H800 Technical Guide 26
Figure 8. Example of RAID 10 (1 + 0)
Advantages of RAID 10
RAID 10 has the same redundancy as RAID level 1
High I/O rates are achieved by striping RAID 1 segments
Allows creation of largest RAID group with up to 192 drives connected to PERC H800
Disadvantages of RAID 10
Most expensive RAID solution
Requires 2n where n > 1 disks
5.3.6 RAID 50 (Striping Across RAID 5)
RAID 50 is a variation of RAID 5 that maps data across two or more RAID 5 virtual disks. The RAID 5
subset must have at least three disks.
Figure 9 illustrates how the parity data is stored. RAID 50
stripes data across each RAID 5 subset. RAID 50 provides a higher degree of fault tolerance since 1
drive per RAID 5 set may fail without data being lost.
A performance increase over RAID 5 may be realized depending on the configuration due to fewer
disks reads per parity calculation.
For example, if a comparison of a RAID 5 virtual disk with 6 disks were made to a RAID 50 virtual disk
with two 3 disk RAID 5 virtual disks, the parity calculation on the RAID 10 virtual disk would require
reading all 6 disks each time, where the parity calculation on the RAID 50 may require only reading
3. This may vary depending on several factors such as cache and data block sizes.
