raid 5 migration

[Neil Morata]

My client has a ML580 server with an existing raid 5. They want to add additional hard disk on their server. What is the right way on adding hard disk on an existing raid 5. Thanks.

[Prashant (I am Back)]

Hi,

You got two options.
(1)
replace old hdd with higher capacity one.
http://h10025.www1.hp.com/ewfrf/wc/genericDocument?lc=en&cc=us&docname=lpn14582

(2)
add new hdd and merger in array.
http://h18000.www1.hp.com/products/servers/proliantstorage/software-management/acumatrix/index.html

For both you need to use acu it will do

Regards,
Prashant S.

[Neil Morata]

do you have a procedure on how to add new hard drives to existing raid 5? Thanks.

[e4services]

Print yourself a copy of the ACU manual for reference.
http://docs.hp.com/en/239449-005/239449-005.pdf
It shows you how to do either.
What was not mentioned was the option of backup and restore. Depending on your clients situation, whether the server is available to go offline or not, this is a viable option. It takes less time if you can take the system offline and you can rebuild the RAID to a more expandable layout, i.e. if the system has 2 logical drives with an OS partition and a data partition you could use the old drives in a RAID 1 for restoring the OS to and the new to restore the data, in a seperate RAID 5 array.

[Steven Clementi]

Neil:


What also was not mentioned is that if yu just add a new drive, and the drive is larger capacity than the existing drives, you will only have the smallest capacity available after expansion.

E.G. you have 4 36GB disks in Array. You expand with 1 72GB disk, you get only 36GB additional space, NOT the full 72GB.


Better option would be to replace each drive with higher capacity if possible. If they are hot plug, you can simply swap one at a time, wait for it to rebuild, swap the next, wait for rebuild.. etc until done. You technically do not even need ACU to complete the swap if you understand and trust the disk lights on the front.

What OS are you running? Also, can you give some detail on your Logical Drive layout?

Steven