From owner-svn-doc-all@FreeBSD.ORG Wed Jul 3 07:15:30 2013 Return-Path: Delivered-To: svn-doc-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) by hub.freebsd.org (Postfix) with ESMTP id 096EC7CB; Wed, 3 Jul 2013 07:15:30 +0000 (UTC) (envelope-from pgj@FreeBSD.org) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:1900:2254:2068::e6a:0]) by mx1.freebsd.org (Postfix) with ESMTP id E02D51136; Wed, 3 Jul 2013 07:15:29 +0000 (UTC) Received: from svn.freebsd.org ([127.0.1.70]) by svn.freebsd.org (8.14.7/8.14.7) with ESMTP id r637FT3D068001; Wed, 3 Jul 2013 07:15:29 GMT (envelope-from pgj@svn.freebsd.org) Received: (from pgj@localhost) by svn.freebsd.org (8.14.7/8.14.5/Submit) id r637FTET068000; Wed, 3 Jul 2013 07:15:29 GMT (envelope-from pgj@svn.freebsd.org) Message-Id: <201307030715.r637FTET068000@svn.freebsd.org> From: Gabor Pali Date: Wed, 3 Jul 2013 07:15:29 +0000 (UTC) To: doc-committers@freebsd.org, svn-doc-all@freebsd.org, svn-doc-head@freebsd.org Subject: svn commit: r42125 - head/en_US.ISO8859-1/htdocs/news/status X-SVN-Group: doc-head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-doc-all@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "SVN commit messages for the entire doc trees \(except for " user" , " projects" , and " translations" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 03 Jul 2013 07:15:30 -0000 Author: pgj Date: Wed Jul 3 07:15:29 2013 New Revision: 42125 URL: http://svnweb.freebsd.org/changeset/doc/42125 Log: - Add Q2 entry on ZFS TRIM Submitted by: smh Modified: head/en_US.ISO8859-1/htdocs/news/status/report-2013-04-2013-06.xml Modified: head/en_US.ISO8859-1/htdocs/news/status/report-2013-04-2013-06.xml ============================================================================== --- head/en_US.ISO8859-1/htdocs/news/status/report-2013-04-2013-06.xml Wed Jul 3 07:02:33 2013 (r42124) +++ head/en_US.ISO8859-1/htdocs/news/status/report-2013-04-2013-06.xml Wed Jul 3 07:15:29 2013 (r42125) @@ -18,7 +18,7 @@

Thanks to all the reporters for the excellent work! This report - contains 11 entries and we hope you enjoy reading it.

+ contains 12 entries and we hope you enjoy reading it.

The deadline for submissions covering between July and September 2013 @@ -548,4 +548,62 @@ yet supported.

+ + + ZFS TRIM and Enhanced <tt>BIO_DELETE</tt> Support + + + + + Pawel Jakub + Dawidek + + pjd@FreeBSD.org + + + + + Steven + Hartland + + smh@FreeBSD.org + + + + +

As of the end of June, &os;'s ZFS implementation now includes + TRIM support in head, stable/9, and + stable/8 branches. This allows ZFS to help maintain + high performance on flash-based devices such as SSD's even under + high-load conditions.

+ +

When creating new pools and adding new devices to existing + pools it first performs a full-device level TRIM to help ensure + optimum starting performance. This behaviour can be overridden + by setting the vfs.zfs.vdev.trim_on_init sysctl + variable to 0 if for example the disks are new or have + already been secure erased, which can also now be done using + camcontrol(8) security actions.

+ +

In order to support TRIM, the kernel requires the underlying + device driver supports BIO_DELETE. This is currently + mapped through to hardware methods such as ATA TRIM and SCSI + UNMAP, which are commonly supported by SSDs via CAM.

+ +

In order to increase the supported hardware base, CAM's SCSI + layer was also enhanced to allow ATA TRIM via SATL ATA + Passthrough to be used in addition to the existing UNMAP and WS + methods. This allows SATA disks attached to SCSI controllers + with CAM based drivers such as mps(4) and + mpt(4) to provide delete support.

+ +

Stats for ZFS TRIM can be monitored by looking at the sysctl + variables under kstat.zfs.misc.zio_trim in addition to + live GEOM delete stats via the gstat -d command.

+ +

This project was sponsored by Multiplay and implemented by + Pawel Jakub Dawidek.

+ +