On Wednesday April 19, ewan.grantham@xxxxxxxxx wrote: > On 4/19/06, Neil Brown <neilb@xxxxxxx> wrote: > > You haven't been following the list have you ..... ;-) > > > > mdadm-2.4.1 plus linux-2.6.17 (or any -rc) can grow a raid5. > > Just add a spare drive and > > mdadm --grow /dev/mdX --raid-disks=N+1 > > Actually I had, but I thought I understood this was extremely > experimental. Does this mean it's considered accepted/acceptable? In > which case, the fact that I'm using a 2.6.15 kernel and mdadm 1.12.0 > (June 2005) (is that version number possibly right?) suggest I need to > do a little tool updating so I can try this out. I presume that I can > upgrade mdadm and then do the grow - or do I need to upgrade and > rebuild the array with the upgraded tool before I can use the grow > option? How much risk do I have of data loss doing this? I think it has transitioned from "Extremely experimental" to "Experimental". If should be safe, and if anything does go wrong, I'm sure I can pick up the pieces for you. But yes, you'll need a tool upgrade. 1.12.0 was the last of the '1' series. 2.4.1 is the latest and is required for raid5 resize. Also, you will need 2.6.17-rc1 or later. And you'll need to select CONFIG_EXPERIMENTAL and the config option to enable raid5 reshaping. You don't need to "upgrade" the array at all, or rebuild it or anything. Risk of data loss is very low. I believe the code is correct and reliable, but until a wide variety of people test it and report success, it is hard to be certain. And as I said, if you do have problem (other than multiple drive failures), I'll do my best to stitch things back together for you. NeilBrown - 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
