[Gluster-devel] Fwd: disperse volume file to subvolume mapping

[Serkan Çoban]

Hi, I just reinstalled fresh 3.7.11 and I am seeing the same behavior.
50 clients copying part-0-xxxx named files using mapreduce to gluster
using one thread per server and they are using only 20 servers out of
60. On the other hand fio tests use all the servers. Anything I can do
to solve the issue?

Thanks,
Serkan


---------- Forwarded message ----------
From: Serkan Çoban <cobanserkan at gmail.com>
Date: Mon, Apr 18, 2016 at 2:39 PM
Subject: disperse volume file to subvolume mapping
To: Gluster Users <gluster-users at gluster.org>


Hi, I have a problem where clients are using only 1/3 of nodes in
disperse volume for writing.
I am testing from 50 clients using 1 to 10 threads with file names part-0-xxxx.
What I see is clients only use 20 nodes for writing. How is the file
name to sub volume hashing is done? Is this related to file names are
similar?

My cluster is 3.7.10 with 60 nodes each has 26 disks. Disperse volume
is 78 x (16+4). Only 26 out of 78 sub volumes used during writes..