Mathias Burén put forth on 1/31/2011 3:41 AM: > How would one go about expanding a 4 HDD RAID10 into a 6 HDD RAID10? > Is it "just" a matter of creating a new RAID1 array of the 2 new HDDs, > then adding them to the RAID0, then expanding whatever is on that > (lvm, xfs, ext4)? The best way to do this "down the road" expansion is to simply create another 4 drive mdraid 10 array and concatenate it to the first with LVM. My guess is that you're more concerned with usable space than IOPs, so you should probably start with a 4 drive RAID5. Down the road, you could add a 3 drive mdraid 5 and concatenate that with the first array using LVM. This will avoid all kinds of potentially messy, possibly earth shattering mdadm conversions. Running such conversions on live arrays without a reliable backup/restore capability is just asking for trouble. Using concatenation leaves your old and new md arrays totally intact. http://linux.about.com/od/commands/l/blcmdl8_lvm.htm > Are there any design tips, or caveats? For example, how many disks > would you use at most, in a RAID10 setup? As many as you want, or that your hardware can support. The largest RAID 10 array I've setup was 40 drives. That was an FC SAN controller though, not mdraid. -- Stan -- 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
