Notes On The Configuration Of Raid 0, 1, 4, 5, And 10 Arrays Drives; Drive Size Dialog; Array Drive Status - Intel SRCU31A - Server RAID U3-1A Controller User Manual

If necessary you can limit the array drive's capacity. In this example the entire capacity of the
drive is used. See Figure 62.
Figure 62. Drive Size Dialog
The array drive enters the build state, for example, the parity information is generated. After
completion of the build process the array drive's state is ready, or fault tolerant. See Figure 63.
Figure 63. Array Drive Status

Notes on the Configuration of RAID 0, 1, 4, 5, and 10 Arrays Drives

Use logical drives of the type disk to build an array drive.
RAID Array drives can be configured with logical drives of the type chain also, but security should
be taken into consideration. For regular RAID Array drives, type disk logical drives are used.
Logical drives of an array drive should have the same storage capacity.
To avoid wasting valuable storage capacity, use only logical drives that have the same storage
capacity as the logical drive being replaced on that array.
A hot fix drive provides the most security.
One of the reasons RAID Array drives are used, lies with the data redundancy they provide, that is,
the data security you have in the event of a hard disk drive failure. For the purpose of the following
considerations, we define the term time without redundancy (TWR) as the time it takes to replace a
failed hard disk drive (assuming there is no hot fix drive installed in the system). The time without
redundancy should be kept as short as possible, not including the time needed to set up the array
drive (state build).
Assume that one of the hard disk drives of a RAID 5 array drive has failed. The array drive is
without redundancy. TWR begins. Any superfluous prolongation of the TWR (because you have
to get a replacement hard disk drive, or because you did not realize the failure immediately since
you didn't hear the Intel RAID Controller SRCU31's alarm signal, or because no one checked the
file server) increases the risk of data loss should a second hard disk drive fail. Therefore, new
redundancy should be created as soon as possible and in an entirely automated manner. Integrate a
hot fix drive as an immediately available and auto-replacing hard disk drive to keep the TWR as
short as possible. Only a hot fix drive can ensure optimal array drive security and constant data
availability. Of course a hot fix drive is not mandatory. If you control the array drive at regular
intervals and immediately replace a defective hard disk drive (by shutting down the system or using
a hot fix), you can minimize the risk of data loss.
120 Intel RAID SRCU31 Users Guide