<html><body><div style="font-family: times new roman, new york, times, serif; font-size: 12pt; color: #000000"><div><br></div><div><br></div><hr id="zwchr"><div style="color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><b>From: </b>"Atin Mukherjee" <atin.mukherjee83@gmail.com><br><b>To: </b>"Raghavendra Talur" <rtalur@redhat.com>, gluster-devel@gluster.org, gluster-users@gluster.org<br><b>Sent: </b>Thursday, March 16, 2017 4:22:41 PM<br><b>Subject: </b>Re: [Gluster-devel] [Gluster-users] Proposal to deprecate replace-brick for "distribute only" volumes<br><div><br></div><div>Makes sense.</div><div><br><div class="gmail_quote"><div>On Thu, 16 Mar 2017 at 06:51, Raghavendra Talur <<a href="mailto:rtalur@redhat.com" target="_blank">rtalur@redhat.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi,<br class="gmail_msg"><br class="gmail_msg">
In the last few releases, we have changed replace-brick command such<br class="gmail_msg">
that it can be called only with "commit force" option. When invoked,<br class="gmail_msg">
this is what happens to the volume:<br class="gmail_msg"><br class="gmail_msg">
a. distribute only volume: the given brick is replaced with a empty<br class="gmail_msg">
brick with 100% probability of data loss.<br class="gmail_msg">
b. distribute-replicate: the given brick is replaced with a empty<br class="gmail_msg">
brick and self heal is triggered. If admin is wise enough to monitor<br class="gmail_msg">
self heal status before another replace-brick command, data is safe.<br class="gmail_msg">
c. distribute-disperse: same as above in distribute-replicate<br class="gmail_msg"><br class="gmail_msg">
My proposal is to fully deprecate replace-brick command for<br class="gmail_msg">
"distribute only" volumes. It should print out a error "The right way<br class="gmail_msg">
to replace brick for distribute only volume is to add brick, wait for<br class="gmail_msg">
rebalance to complete and remove brick" and return a "-1".<br class="gmail_msg"></blockquote><div><br></div><div>It makes sense.<br></div><div>I just don't see any use of add-brick before remove-brick except the fact that it will</div><div>help to keep the overall storage capacity of volume intact . </div><div>What is the guarantee that the files on the brick which we want to replace </div><div>would migrate to added brick?<br></div><div><br></div><div>If a brick, which we want to replace, is healthy and we just want to replace it then perhaps we should provide <br></div><div>a command to copy those files to new brick and then remove the old brick. <br></div><div><br></div><div><br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Thoughts?<br class="gmail_msg"><br class="gmail_msg">
Thanks,<br class="gmail_msg">
Raghavendra Talur<br class="gmail_msg">
_______________________________________________<br class="gmail_msg">
Gluster-users mailing list<br class="gmail_msg"><a href="mailto:Gluster-users@gluster.org" class="gmail_msg" target="_blank">Gluster-users@gluster.org</a><br class="gmail_msg"><a href="http://lists.gluster.org/mailman/listinfo/gluster-users" rel="noreferrer" class="gmail_msg" target="_blank">http://lists.gluster.org/mailman/listinfo/gluster-users</a><br class="gmail_msg"></blockquote></div></div><div dir="ltr">-- <br></div><div>--Atin</div>
<br>_______________________________________________<br>Gluster-devel mailing list<br>Gluster-devel@gluster.org<br>http://lists.gluster.org/mailman/listinfo/gluster-devel</div><div><br></div></div></body></html>