Fault Tolerance; The Smart Feature - Dell PowerEdge H730P User Manual

Source RAID

Target RAID

Level

Level

RAID 5

RAID 5

RAID 5

RAID 6

RAID 6

RAID 0

RAID 6

RAID 5

RAID 6

RAID 6

NOTE: The total number of physical disks in a disk group cannot exceed 32. You cannot perform

RAID level migration and expansion on RAID levels 10, 50, and 60.

The PERC H730P card supports the following:

•

Self Monitoring and Reporting Technology (SMART)

•

Patrol Read

•

Physical disk failure detection

•

Physical disk rebuild using hot spares

•

Controller cache preservation

•

Battery and non-volatile cache backup of controller cache to protect data

•

Detection of batteries with low charge after boot up

The next sections describe some methods to achieve fault tolerance.

The SMART feature monitors certain physical aspects of all motors, heads, and physical disk electronics

to help detect predictable physical disk failures. Data on SMART-compliant physical disks can be

Number of

Number of

Physical Disks

Physical Disks

(Beginning)

(End)

3 or more

4 or more

3 or more

4 or more

4 or more

4 or more

4 or more

4 or more

4 or more

5 or more

Capacity

Description

Expansion

Possible

Yes

Increases

capacity by

adding disks.

Yes

At least one

disk needs to

be added for

dual distributed

parity data.

Yes

Converts to a

non-redundant

virtual disk and

reclaims disk

space used for

distributed

parity data.

Yes

Removes one

set of parity

data and

reclaims disk

space used for

it.

Yes

Increases

capacity by

adding disks

23