<html><body><div style="font-family: times new roman, new york, times, serif; font-size: 12pt; color: #000000"><div>Hi Terry,<br></div><div><br></div><div>There is not constraint on number of nodes for erasure coded volumes. <br></div><div>However, there are some suggestions to keep in mind.<br></div><div><br></div><div>If you have 4+2 configuration, that means you can loose maximum 2 bricks at a time without loosing your volume for IO. <br></div><div>These bricks may fail because of node crash or node disconnection. That is why it is always good to have all the 6 bricks on 6 different nodes. If you have 3 bricks on one node and this nodes goes down then you<br></div><div>will loose the volume and it will be inaccessible.</div><div>So just keep in mind that you should not loose more than redundancy bricks even if any one node goes down.<br></div><div><br></div><div>----<br></div><div>Ashish<br></div><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;" data-mce-style="color: #000; font-weight: normal; font-style: normal; text-decoration: none; font-family: Helvetica,Arial,sans-serif; font-size: 12pt;"><b>From: </b>"Terry McGuire" <tmcguire@ualberta.ca><br><b>To: </b>gluster-users@gluster.org<br><b>Sent: </b>Wednesday, March 29, 2017 11:59:32 PM<br><b>Subject: </b>[Gluster-users] Node count constraints with EC?<br><div><br></div>Hello list. Newbie question: I’m building a low-performance/low-cost storage service with a starting size of about 500TB, and want to use Gluster with erasure coding. I’m considering subvolumes of maybe 4+2, or 8+3 or 4. I was thinking I’d spread these over 4 nodes, and add single nodes over time, with subvolumes rearranged over new nodes to maintain protection from whole node failures.<div class=""><br class=""></div><div class="">However, reading through some RedHat-provided documentation, they seem to suggest that node counts should be a multiple of 3, 6 or 12, depending on subvolume config. Is this actually a requirement, or is it only a suggestion for best performance or something?</div><div class=""><br class=""></div><div class="">Can anyone comment on node count constraints with erasure coded subvolumes?</div><div class=""><br class=""></div><div class="">Thanks in advance for anyone’s reply,</div><div class="">Terry</div><div class=""><br class=""></div><div class=""><div style="color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;" data-mce-style="color: #000000; font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;">_____________________________<br class="">Terry McGuire<br class="">Information Services and Technology (IST)<br class="">University of Alberta<br class="">Edmonton, Alberta, Canada T6G 2H1<br class="">Phone: 780-492-9422</div><div style="color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;" data-mce-style="color: #000000; font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;"><br class=""></div></div><br>_______________________________________________<br>Gluster-users mailing list<br>Gluster-users@gluster.org<br>http://lists.gluster.org/mailman/listinfo/gluster-users</div><div><br></div></div></body></html>