Expanding an array, Extending a logical drive, Managing spare drives – HP StorageWorks 1500cs Modular Smart Array User Manual

Page 52

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Using the Command Line Interface 52

Expanding an array

You can increase the storage space on an array by adding physical drives. However, the added drives
must be of the same type (for example, parallel SCSI or SATA), and they must each have a capacity no
less than that of the existing drives in the array.

IMPORTANT: An array expansion, logical drive extension, or logical drive migration takes about 15

minutes per gigabyte, or considerably longer if the controller does not have a battery-backed cache. While
this process is occurring, no other expansion, extension, or migration can occur simultaneously on the same
controller.

Syntax:

<target> add drives=[#:]#:#,[#:]#:#,[#:]#:#–[#:]#:#,...|allunassigned

[forced]

where

<target>

is an array (or a logical drive, if the array contains only one logical drive). The

parameter

forced

represses warning message prompts.

If you add an odd number of drives to an array that contains at least one RAID 1+0 logical drive, the CLI
displays a prompt that asks if it is acceptable to convert the RAID 1+0 logical drive to RAID 5 (or RAID 6
(ADG) if the controller supports this RAID level). Adding the

forced

parameter to the command prevents

this prompt from appearing.

Example commands:

=> ctrl slot=3 array A add drives=1:0,1:1

=> ctrl slot=4 ld 1 add drives=allunassigned

=> ctrl slot=5 array A add drives=1:1–1:5

Extending a logical drive

If the operating system supports logical drive extension, you can use any unassigned capacity on an
array to enlarge one or more of the logical drives on the array.

IMPORTANT: An array expansion, logical drive extension, or logical drive migration takes about 15

minutes per gigabyte, or considerably longer if the controller does not have a battery-backed cache. While
this process is occurring, no other expansion, extension, or migration can occur simultaneously on the same
controller.

Syntax:

<target> modify size=#|max|? [forced]

where

<target>

is a logical drive.

If the operating system does not support logical drive extension, carrying out this command would make
data on the logical drive unavailable. Therefore, the CLI displays a warning prompt as a safeguard in
case you are using such an operating system. To prevent the prompt from appearing, use the

forced

parameter.

Example commands:

=> ctrl slot=3 ld 1 modify size=max

=> ctrl slot=4 ld 1 modify size=?

=> ctrl slot=3 ld 2 modify size=500 forced

Managing spare drives

Assigning online spares to an array enables you to postpone replacement of faulty drives. However, it
does not increase the fault-tolerance level of any logical drives in the array. For example, a logical drive
in a RAID 5 configuration suffers irretrievable data loss if two physical drives fail, regardless of the
number of spare drives assigned to it.

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