2011/8/22 MORITA Kazutaka <morita.kazutaka at lab.ntt.co.jp>: > I'm not sure this answers your questions, but currently you need to > run multiple sheep daemons to handle multiple directories. "Multiple sheep daemons" means run more time 'sheep <dorectory>" right? I did this: created a cluster on two nodes. storage1 'sheep /sheep_data' (sda6) storage2 'sheep /sheep_data' (sda6) I run a vm and chunks have been writen on the two directories. Then I added two directories: storage1 'sheep /sheep_data2' (sdb6) storage2 'sheep /sheep_data2' (sdb6) No data have been writen in these last two directories. I also run 'dd if=/dev/zero of=tmp bs=1M count=2048' on the vm to make it grow. Are the last two directories going to be used when no space is lefet on the firts two? >> If I shutdown a node after the other... > As you may know, you should run "collie cluster shutdown" before > stopping a Sheepdog cluster to avoid extra data copies.. No, I didn't know. Honestly I do no have very clear how sheepdog manage the chunks when a node goes down (e.g. black out). Or better: I aspect sheepdog to find out the chunks that have a single copy and replicate them in the available nodes. What is less clear to me is: what happens when the node comes up again? In the scenario of 3 nodes with copies=2, the third node goes down for some time; it's data should be replicated on the two nodes left; when it's back, it still have the 'old' chunks (some might be changed, some not)... So we have extra redoundance for some chunks plus some 'old/trash' chunks. How does sheepdog manage this? What happens when I do "collie cluster shutdown"? Thank you for the answers. |