Online Capacity Expansion with LSI RAID controller

[coolrunnings]

Ok so according to the documentation of my RAID controller, an LSI Logic 8308ELP, the card is supposed to support Online Capacity Expansion. I currently have a RAID 5 set up with 4 disks and want to add 2 more drives to increase the capacity without losing data. However I have no idea how to do this and I can't seem to find any documentation on it either. Can anyone walk me through how to do this?

 

[drizzt81]

• buy disks
• install disks
• use either controller BIOS or supplied management software for current OS to expand array
• depending on OS, grow partitions

 

[axan]

pretty much what ^ said, but depending on os and file system you use it will either be a snap or impossible.

 

[Rocco123]

Even with Windows basic partitions, it's not impossible to expand. You'd use diskpart or use partitionmagic.

You shouldn't need to do this in BIOS (hence online disk expansion. There should be an option to expand in the Megaraid Storage Manager. I'd have to double check on the exact steps, but it should be pretty easy to determine how to do it when you go into the storage mgr.

 

[axan]

When i said it's impossible in certain situations I wasn't referring to windows. Windows drives are pretty easy to expand. But for example if you use something like freenas or any freebsd os with gpt partitions (you have to if your array is > 2 TB) there is no utility for resizing the gpt partition tables so it's impossible to expand your array.

Don't think there are any gpt resize utilities for linux either but you can just run xfs without partitions and then expanding your array takes 10 seconds (+ time for the controller to go through oce/rebuild)

 

[coolrunnings]

Finally found the option for expanding... Took 16 hours to add 2 drives to the array but boy was it worth it. I saw a jump from 120mb/s to 195mb/s maximum transfer rates and a very linear performance increase across the board. RAID 5 rocks!