How to remove phys drives from logical drive?

[josbal]

Hi All,

I have a RHEL5 server with 6 phys drives in a raid 5 logical drive. We would like to remove 3 of these disk as the capacity is not being used.

Can anyone give an idea as to how i can acheive this with hpacucli or other such tools? I have already reduced the fs and lvms, just need to know a process for removing disks from the logical drive of the array.

Cheers.

[Matti_Kurkela]

First, do you have a hardware RAID controller or are you using RHEL 5 software RAID? If you have a hardware RAID controller, which model it is?

Since you mention hpacucli, I assume you're using some model of HP SmartArray hardware RAID controller.

Different controller models allow different types of modifications to the RAID sets: in particular, a controller with a battery- or flash-backed write cache module is usually more flexible than one without it.

Here's the SmartArray controller configuration reference guide:

http://bizsupport2.austin.hp.com/bc/docs/support/SupportManual/c00729544/c00729544.pdf

The hpacucli syntax for shrinking an array is explained on pages 66-67.

Essentially, you tell the controller which drives you want to remove from the RAID set. The controller may reject the command if it cannot do it safely. If the command is doable, the controller will then rearrange the data to make the removal possible. Obviously you should wait until the data rearrangement operation is complete before actually removing the disks.