Hi Graham and Josh, On Wed, 2011-06-29 at 18:25 -0700, Josh Durgin wrote: > > 2) What is the procedure for adding an additional hard drive to each OSD? I have a second 2TB drive physically on each OSD node that I would like to bring up and I did not find ready documentation on just adding drives. > > The simplest way to add a drive is to start a new OSD for the new drive. > Instructions for this are on the wiki: > > http://ceph.newdream.net/wiki/OSD_cluster_expansion/contraction > > Since your new drive is the same size as the others, you wouldn't need > to adjust your crush map to get an even distribution of data. You still need to add it to your crush map, but you don't need to fiddle with the weight of the OSDs ;-) Just to make it clear for Graham, you do need to add the new OSDs to your crush map as new devices, but the weight isn't needed since they're all of equal size. > > The downside of running one OSD per disk is increased memory and cpu > usage, but this shouldn't be a problem with a small cluster and few PGs. Yes, I can confirm that. I currently have 40 OSD's and +10k PG's, this is hitting my machines pretty hard. The machines are Atoms with 4GB of RAM each and 4 OSD's (2TB) per machine. Wido -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
