<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>"Serkan Çoban" <cobanserkan@gmail.com><br><b>To: </b>"Gluster Users" <gluster-users@gluster.org><br><b>Sent: </b>Monday, May 29, 2017 5:13:06 PM<br><b>Subject: </b>[Gluster-users] Heal operation detail of EC volumes<br><div><br></div>Hi,<br><div><br></div>When a brick fails in EC, What is the healing read/write data path?<br>Which processes do the operations?<br><div><br></div><div>Healing could be triggered by client side (access of file) or server side (shd).<br></div><div>However, in both the cases actual heal starts from "ec_heal_do" function.<br></div><div><br></div><div><br></div>Assume a 2GB file is being healed in 16+4 EC configuration. I was<br>thinking that SHD deamon on failed brick host will read 2GB from<br>network and reconstruct its 100MB chunk and write it on to brick. Is<br>this right?</div><div style="color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><br></div><div style="color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;">You are correct about read/write.<br></div><div>The only point is that, SHD deamon on one of the good brick will pick the index entry and heal it.<br></div><div style="color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;">SHD deamon scans the .glusterfs/index directory and heals the entries. If the brick went down while IO was going on, index will be present on killed brick also.</div><div style="color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;">However, if a brick was down and then you started writing on a file then in this case index entry would not be present on killed brick.<br></div><div style="color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;">So even after brick will be UP, sdh on that brick will not be able to find it out this index. However, other bricks would have entries and shd on that brick will heal it.<br></div><div style="color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><br></div><div style="color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;">Note: I am considering each brick on different node.</div><div style="color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><br></div><div style="color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;">Ashish<br></div><div style="color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><br></div><div style="color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><br></div><div style="color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><br></div><div style="color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><br></div><div style="color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><br></div><div style="color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><br></div><div style="color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><br></div><div style="color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><br></div><div style="color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><br></div><div style="color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><br>_______________________________________________<br>Gluster-users mailing list<br>Gluster-users@gluster.org<br>http://lists.gluster.org/mailman/listinfo/gluster-users<br></div><div><br></div></div></body></html>