Date: Wed, 3 Jul 2013 07:15:29 +0000 (UTC) From: Gabor Pali <pgj@FreeBSD.org> 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 Message-ID: <201307030715.r637FTET068000@svn.freebsd.org>
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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 @@ <!-- XXX: keep updating the number of entries --> <p>Thanks to all the reporters for the excellent work! This report - contains 11 entries and we hope you enjoy reading it.</p> + contains 12 entries and we hope you enjoy reading it.</p> <!-- XXX: set date for the next set of submissions --> <p>The deadline for submissions covering between July and September 2013 @@ -548,4 +548,62 @@ yet supported.</p> </body> </project> + + <project cat='kern'> + <title>ZFS TRIM and Enhanced <tt>BIO_DELETE</tt> Support</title> + + <contact> + <person> + <name> + <given>Pawel Jakub</given> + <common>Dawidek</common> + </name> + <email>pjd@FreeBSD.org</email> + </person> + + <person> + <name> + <given>Steven</given> + <common>Hartland</common> + </name> + <email>smh@FreeBSD.org</email> + </person> + </contact> + + <body> + <p>As of the end of June, &os;'s ZFS implementation now includes + TRIM support in <tt>head</tt>, <tt>stable/9</tt>, and + <tt>stable/8</tt> branches. This allows ZFS to help maintain + high performance on flash-based devices such as SSD's even under + high-load conditions.</p> + + <p>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 <tt>vfs.zfs.vdev.trim_on_init</tt> sysctl + variable to <tt>0</tt> if for example the disks are new or have + already been secure erased, which can also now be done using + <tt>camcontrol(8)</tt> security actions.</p> + + <p>In order to support TRIM, the kernel requires the underlying + device driver supports <tt>BIO_DELETE</tt>. This is currently + mapped through to hardware methods such as ATA TRIM and SCSI + UNMAP, which are commonly supported by SSDs via CAM.</p> + + <p>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 <tt>mps(4)</tt> and + <tt>mpt(4)</tt> to provide delete support.</p> + + <p>Stats for ZFS TRIM can be monitored by looking at the sysctl + variables under <tt>kstat.zfs.misc.zio_trim</tt> in addition to + live GEOM delete stats via the <tt>gstat -d</tt> command.</p> + + <p>This project was sponsored by <a + href="http://www.multiplay.com">Multiplay</a>; and implemented by + Pawel Jakub Dawidek.</p> + </body> + </project> </report>
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