On Fri, Mar 12, 2010 at 3:39 AM, Patrick J. LoPresti <lopresti@xxxxxxxxx> wrote: > From reading the documentation and source code, I gather "mdadm > --grow" is not supported for RAID-0 devices. > > In my application, I am using md RAID-0 to stripe among several > (identical) hardware RAID-0 chassis. I would like to extend my setup > by adding another chassis, but apparently, I cannot (?). > > The next time I build a system like this, is there any way to get what > I want using Linux? That is, striping among devices, no parity, but > with the ability to grow in the future? I agree with others on the list - I believe that LVM will perform well as a flexible stripe wrangler on top of mdadm arrays. For instance some LVM striping over mdadm parity-based stuff underneath. Do you want to add a whole new stripe device, so changing the coarse-scale layout, or grow the underlying data containers? I had a problem related to growing underlying containers which was solved on the list a few weeks ago. I had two largish RAID6 arrays and an mdadm stripe-set over those. I added some disks to both RAID6 subarrays and wanted to expand the stripe-array to use the space gained. Here's a copy of the thread, "raid0 not growable?": http://www.issociate.de/board/post/501375/raid0_not_growable?.html But perhaps you wanted to do something like add a 3rd stripe to a two-stripe array? (I myself don't know if that's possible or not.) As you are running striped, I assume that the data is either perishable or backed up. I'd suggest you look into moving to LVM. (LVM has its quirks - so look before you leap, perhaps :) ) I suggest you play a little with LVM in a virtual-machine; In the gas-lit and magical world of open-source RAID management, there's nothing like direct experience to tell you what's possible and what doesn't work. The tools and the power are out there, but you have to do a little hunting in the forest. Best of luck! -- Kristleifur -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
