Intel SRCMR, User Manual

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Storage Console 119
If necessary you can limit the array drive’s capacity. In this example the entire capacity of the
drive is used. See Figure 64.
Figure 64. 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 65.
Figure 65. 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 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 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 disks 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, or because you did not realize the failure immediately since you didn’t hear
the Intel RAID Controller SRCMR’s alarm signal, or because no one checked the file server)
increases the risk of data loss should a second hard disk 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 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 (by shutting down the system or using a hot fix), you can minimize the
risk of data loss.