+++ This bug was initially created as a clone of Bug #1356076 +++
Description of problem:
On a pure distributed volume with one brick being a FreeBSD node with ZFS as filesystem and the other a Linux, dht puts ten more times data on FreeBSD node (3 TB vs 30 TB)
Version-Release number of selected component (if applicable): mainline
Steps to Reproduce:
1. Create a distributed volume with two bricks: one on a FreeBSD/ZFS and another one on a CentOS
2. Start copying files
almost all files are placed in the FreeBSD node.
nearly 50% of files should be placed in each node.
A "gluster volume status detail" command shows a space on FreeBSD filesystem much bigger that it really is (~256 times bigger). It also doesn't detect the filesystem and some other information:
File System : N/A
Device : N/A
Mount Options : N/A
Inode Size : N/A
Disk Space Free : 2.6PB
Total Disk Space : 12.6PB
Real brick space is 45TB
A statvfs() call on FreeBSD returns this:
From statvfs() man page on FreeBSD:
"The statvfs() and fstatvfs() functions fill the structure pointed to by
buf with garbage. This garbage will occasionally bear resemblance to
file system statistics, but portable applications must not depend on
this. Applications must pass a pathname or file descriptor which refers
to a file on the file system in which they are interested."
"f_frsize The size in bytes of the minimum unit of allocation on
this file system. (This corresponds to the f_bsize mem-
ber of struct statfs.)"
"f_bsize The preferred length of I/O requests for files on this
file system. (Corresponds to the f_iosize member of
Probably gluster uses f_bsize as the block size, but on FreeBSD it's the optimal I/O size, not the block size.
As a workaround, disabling 'weighted-rebalance' distributes files evenly between bricks.
--- Additional comment from Jeff Darcy on 2016-07-13 17:54:25 CEST ---
You're probably right, Xavier. Unfortunately, Linux and FreeBSD seem to have some fundamental disagreements about what these fields mean, so we'll probably have to add some platform-conditional code in some of the several places that use them. I also doubt that this is the last problem we'll find in OS-heterogeneous clusters. :(
--- Additional comment from Xavier Hernandez on 2016-07-14 08:17:25 CEST ---
We are using wrapped system calls in many places right now (syscall.h). Maybe we should enforce the usage of these wrappers and place the specific OS code in syscall.c.
For this particular case we could solve the problem simply by setting f_bsize = f_frsize on FreeBSD.
REVIEW: http://review.gluster.org/16398 (libglusterfs: fix statvfs in FreeBSD) posted (#1) for review on release-3.9 by Xavier Hernandez (firstname.lastname@example.org)
COMMIT: http://review.gluster.org/16398 committed in release-3.9 by Kaleb KEITHLEY (email@example.com)
Author: Xavier Hernandez <firstname.lastname@example.org>
Date: Mon Jan 9 13:10:19 2017 +0100
libglusterfs: fix statvfs in FreeBSD
FreeBSD interprets statvfs' f_bsize field in a different way than Linux.
This fix modifies the value returned by statvfs() on FreeBSD to match
the expected value by Gluster.
> Change-Id: I930dab6e895671157238146d333e95874ea28a08
> BUG: 1356076
> Signed-off-by: Xavier Hernandez <email@example.com>
> Reviewed-on: http://review.gluster.org/16361
> Smoke: Gluster Build System <firstname.lastname@example.org>
> NetBSD-regression: NetBSD Build System <email@example.com>
> Reviewed-by: Kaleb KEITHLEY <firstname.lastname@example.org>
> CentOS-regression: Gluster Build System <email@example.com>
> Reviewed-by: Jeff Darcy <firstname.lastname@example.org>
Signed-off-by: Xavier Hernandez <email@example.com>
Smoke: Gluster Build System <firstname.lastname@example.org>
NetBSD-regression: NetBSD Build System <email@example.com>
Reviewed-by: Kaleb KEITHLEY <firstname.lastname@example.org>
CentOS-regression: Gluster Build System <email@example.com>
REVIEW: https://review.gluster.org/16632 (extras/rebalance.py: Fix statvfs for FreeBSD in python) posted (#1) for review on release-3.9 by Xavier Hernandez (firstname.lastname@example.org)
This bug is getting closed because a release has been made available that should address the reported issue. In case the problem is still not fixed with glusterfs-3.9.1, please open a new bug report.
glusterfs-3.9.1 has been announced on the Gluster mailinglists , packages for several distributions should become available in the near future. Keep an eye on the Gluster Users mailinglist  and the update infrastructure for your distribution.