When will software RAID hotswap work?
So, when will software RAID hotswap work? Or, is it just one of those things that is just infeasible?
We'd like to use this for our lower-end boxes (1U, 4 hard drive), so we don't have to waste money or slots with a raid controller. At this low end, software raid and hardware raid are pretty close in performance (not counting controller cache), and one of the boxes we use has a special connector that hooks up from the hot-swap back-plane to the motherboard, so it'd be kind of a pain to have to get another kind of cable to hook up to a hardware raid controller.
We dont have any plans for this as I believe it is hardware related.
All the best,
In linux, it is possible to do a software raid hot-swap without rebooting or making the array unavailable, but you have to do it manually (i.e. log in as an administrator and run some commands). This is fine and preferable if you only have 4 drives (with no hot spare), where you're going to manually add a drive anyways. Perhaps this can be added to the mile-long list of feature requests?
I believe there's a kernel patch that supports hot-plugging and "warm-plugging" (whatever the heck that means). It's called libata. I guess I'll just have to wait until it's included in the mainstream kernel.
Hmmm... Maybe hot-plugging/swapping IS supported under the mainline kernel? I haven't tried yet with the new version of Open-E. I'll try it out and tell you if it works. Who knows? Perhaps the new kernel version will allow it to "Just Work (R)."
Here's a link to someone who seems to be entirely satisfied with hot-swapping and software RAID under linux: