From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Bryant G. Ly" Date: Wed, 25 Apr 2018 13:46:23 +0000 Subject: Re: MaxTransferLength Message-Id: <64d0a230-e7ce-8b0b-e38f-ca2b7d86358a@linux.vnet.ibm.com> List-Id: References: <20180424122512.GQ27687@hydro.skol.ch> In-Reply-To: <20180424122512.GQ27687@hydro.skol.ch> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: target-devel@vger.kernel.org On 4/25/18 5:13 AM, Nicolas D wrote: > Hello, > > On Tue, Apr 24, 2018 at 07:53:53AM -0500, Bryant G. Ly wrote: >> On 4/24/18 7:38 AM, Hannes Reinecke wrote: >> >>> 'pscsi' is the SCSI pass-through, so it'll be presenting the >>> values from the underlying device; I doubt you can change that. > I have tried to tweak /sys/block/sr0/queue/max_sectors_kb but with no > luck (sr0 is the backend exported) Can you tell me if targetcli use this > value? And if yes, when is it taken into account? (on backend creation? > when the initiator connects? sometime else?) > >>> What you could try is to mount the DVD, and export the mountpoint >>> via the file backend; that way you should be able to tweak the >>> parameters. > I forgot to say that the goal is to play dvd/bd video disks and that I > need the pass-through for all the special commands needed to authenticate > the drive etc. So using the file backend does not seem to be an option. > >> Adding to what Hannes is saying, if you need true dvd/cd emulation you can >> use file optical media backstore via user:fbo from tcmu-runner. > Does the user:fbo handle the necessary special command for video dvd/bd? > > Yes, user:fbo was written specifically to emulate optical drives, so it should handle all the commands you need for dvd. Bryant