Number Of Physical Disks Supported; Physical Devices Required For Each Raid Level - IBM ServeRAID-MR10M User Manual

1.4.1

Number of Physical Disks Supported

Your configuration planning for the ServeRAID-MR10M controller
depends in part on the number of physical disks that you want to use in
a RAID array. The number of drives in an array determines the RAID
levels that can be supported by this controller. Only one RAID level can
be assigned to each virtual disk.
Table 1.1 summarizes the minimum number of physical disks required
and the maximum number of physical disks allowed to configure one
virtual disk for each possible RAID level.
Each enclosure added consumes a physical disk, so the actual number
of physical disks available for configuration depends on the number of
enclosures used in the system.
Note that the maximum number of physical disks available for
configuration could be less than the 256 listed in the table.
In addition, the minimum number of physical disks allowed could be
different if the virtual disk is imported from a foreign configuration. This
is because the MegaRAID utilities allow the import of degraded foreign
virtual disks.
Table 1.1

Physical Devices Required for Each RAID Level

RAID Minimum # of
Level Physical Devices
0
1*
5
6
10
50
60
* - The information for RAID level 1 includes PRL 11, also. PRL 11
consists of mirrored pairs of disks, where each mirrored pair behaves as
a RAID 1 array. A PRL 11 RAID set can have up to eight mirrored pairs
of disks.
Configuration Scenarios
Maximum # of
Physical Devices
1
2
3
3
4
6
6
32
16
32
32
16
256
256
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