Bug 659884

Summary:	Use posix_fallocate in write paths
Product:	Red Hat Enterprise Linux 6	Reporter:	Simo Sorce <ssorce>
Component:	samba	Assignee:	Guenther Deschner <gdeschner>
Status:	CLOSED ERRATA	QA Contact:	Ales Zelinka <azelinka>
Severity:	medium	Docs Contact:
Priority:	low
Version:	6.1	CC:	azelinka, dpal, esandeen, gdeschner, jra, mishu, prc
Target Milestone:	rc
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	samba-3.5.4-81.el6	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2011-05-19 13:14:39 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Simo Sorce 2010-12-03 23:14:24 UTC

upstream has a patch for 3.5 that can potentially increase performances on ext4/xfs by using posix_fallocate.

We should consider applying it to RHEL6 samba.
Potentially we could also consider turning strict allocate to true by patching it in as a default in loadparm.c

The upstream bug is here: https://bugzilla.samba.org/show_bug.cgi?id=7835

Comment 3 Jeremy Allison 2010-12-03 23:38:37 UTC

+1 from me. Keep me posted on the progress on this one. It can *double* Samba
performance in applications which write large files. I will push to get "strict
allocate" set to "true" in upstream code in 3.6.0, but Red Hat can gain this
performance now if you apply this change to your 3.5.x tree.

Jeremy.

Comment 7 Eric Sandeen 2010-12-09 17:02:24 UTC

Jeremy tested with:

"In tests done on an ext4 file system, changing to "strict allocate =
yes" and using the posix_fallocate() call in this way increased the
write performance of Samba by 2/3 on a NETGEAR ReadyNAS box as
tested by the Intel NASPT test tool, available here:

http://software.intel.com/en-us/articles/intel-nas-performance-toolkit/

The specific tests used to measure the performance increase were the
"File Copy to NAS" and the "HD Video Record" tests."

We should do the same or similar for all the filesystems we support with Samba - at least ext3, ext4, xfs.

Thanks,
-Eric

Comment 12 errata-xmlrpc 2011-05-19 13:14:39 UTC

An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHBA-2011-0582.html