7
Figure 8 RAID 5
When a physical drive fails, data that was on the failed drive can be calculated from the remaining
parity data and user data on the other drives in the array. This recovered data is usually written to
an online spare in a process called a rebuild.
Application scenarios
RAID 5 is useful when cost, performance, and data availability are equally important.
Advantages
•
Has high read performance.
•
Data is not lost if only one physical drive fails.
•
More drive capacity is usable than with RAID 10, because parity information requires only the
storage space equivalent to one physical drive.
Disadvantages
•
Has relatively low write performance.
•
Data is lost if a second drive fails before data from the first failed drive is rebuilt.
RAID 6
As shown in
, RAID 6, like RAID 5, generates and stores parity information to protect
against data loss caused by drive failure. However, RAID 6 uses two different sets of parity data
(denoted by P
x,y
and Q
x,y
), allowing data to still be preserved if two drives fail. Each set of parity data
uses a capacity equivalent to that of one of the constituent drives.
Summary of Contents for UniServer R4300 G6
Page 36: ...21 Figure 23 Selecting the controller and RAID level 4 Select drives and then click Next...
Page 40: ...25 Figure 27 Selecting the RAID array to be deleted 2 In the dialog box that opens click Yes...
Page 66: ...24 Figure 37 Confirming RAID creation 7 Click OK to complete the RAID creation...
Page 164: ...89 Figure 158 Selecting Main Menu 2 Select Controller Management and press Enter...
Page 321: ...90 Figure 138 Configure Controller Settings screen for the RAID P460 B2...
Page 469: ...19 Examples Viewing physical drive informatoin Syntax mnv_cli info o pd Examples...
Page 513: ...7 Figure 10 Selecting Drive Management 4 Select the target drive and then press Enter...
Page 514: ...8 Figure 11 Select the target drive 5 View the value of the Status field...
Page 529: ...23 Figure 33 Identifying a storage controller 2...