From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ric Wheeler Subject: Re: copy offload support in Linux - new system call needed? Date: Wed, 14 Dec 2011 15:30:11 -0500 Message-ID: <4EE90753.6060700@gmail.com> References: <4EE8F75F.6070800@gmail.com> <20111214195931.GC10664@samba2> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: "linux-scsi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , linux-fsdevel , Hannes Reinecke , Andrew Morton , linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Joel Becker , James Bottomley To: Jeremy Allison Return-path: In-Reply-To: <20111214195931.GC10664@samba2> Sender: linux-nfs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-fsdevel.vger.kernel.org On 12/14/2011 02:59 PM, Jeremy Allison wrote: > On Wed, Dec 14, 2011 at 02:22:07PM -0500, Ric Wheeler wrote: >> Back at LinuxCon Prague, we talked about the new NFS and SCSI >> commands that let us offload copy operations to a storage device >> (like an NFS server or storage array). >> >> This got new life in the virtual machine world where you might want >> to clone bulky guest files or ranges of blocks and was driven >> through the standards bodies by vmware, microsoft and some of the >> major storage vendors. Windows8 has this functionality fully coded >> and integrated in the GUI, I assume vmware also uses it and there >> are some vendors who announced support at the SNIA SDC conference. >> >> We had an active thread a couple of years back that came out of the >> reflink work and, at the time, there seemed to be moderately >> positive support for adding a new system call that would fit this >> use case (Joel Becker's copyfile()). >> >> Can we resurrect this effort? Is copyfile() still a good way to go, >> or should we look at other hooks? > Windows uses a COPYCHUNK call, which specifies the > following parameters: > > Definition of a copy "chunk": > > hyper source_off; > hyper target_off; > uint32 length; > > and an array of these chunks which is passed > into their kernel. > > This is what we have to implement in Samba. > > Jeremy. This is a public pointer to the draft NFS proposal: http://tools.ietf.org/id/draft-lentini-nfsv4-server-side-copy-06.txt The T10 site has some click through that I was not too happy about agreeing to. NetApp (Fred Knight) had some nice presentations that he presented about how SCSI does this in two different ways... Ric -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html