<div dir="ltr"><br><div class="gmail_extra"><br><div class="gmail_quote">On Tue, May 2, 2017 at 12:20 AM, Gandalf Corvotempesta <span dir="ltr"><<a href="mailto:gandalf.corvotempesta@gmail.com" target="_blank">gandalf.corvotempesta@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><span class="">2017-05-01 20:43 GMT+02:00 Shyam <<a href="mailto:srangana@redhat.com">srangana@redhat.com</a>>:<br>
> I do agree that for the duration a brick is replaced its replication count<br>
> is down by 1, is that your concern? In which case I do note that without (a)<br>
> above, availability is at risk during the operation. Which needs other<br>
> strategies/changes to ensure tolerance to errors/faults.<br>
<br>
</span>Oh, yes, i've forgot this too.<br>
<br>
I don't know Ceph, but Lizard, when moving chunks across the cluster,<br>
does a copy, not a movement<br>
During the whole operation you'll end with some files/chunks<br>
replicated more than the requirement.<br></blockquote><div><br></div><div>Replace-brick as a command is implemented with the goal of replacing a disk that went bad. So the availability was already less. In 2013-2014 I proposed that we do it by adding brick to just the replica set and increase its replica-count just for that set once heal is complete we could remove this brick. But at the point I didn't see any benefit to that approach, because availability was already down by 1. But with all of this discussion it seems like a good time to revive this idea. I saw that Shyam suggested the same in the PR he mentioned before.<br></div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<br>
If you have a replica 3, during the movement, some file get replica 4<br>
In Gluster the same operation will bring you replica 2.<br>
<br>
IMHO, this isn't a viable/reliable solution<br>
<br>
Any change to change "replace-brick" to increase the replica count<br>
during the operation ?<br>
</blockquote></div>It can be done. We just need to find time to do this.<br></div><div class="gmail_extra"><br clear="all"><br>-- <br><div class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr">Pranith<br></div></div>
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