From owner-freebsd-hackers@FreeBSD.ORG Mon Sep 23 16:05:21 2013 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTP id 0FC3333F; Mon, 23 Sep 2013 16:05:21 +0000 (UTC) (envelope-from rp_freebsd@mac.com) Received: from st11p00mm-asmtp003.mac.com (st11p00mm-asmtp003.mac.com [17.172.81.2]) by mx1.freebsd.org (Postfix) with ESMTP id DAE582749; Mon, 23 Sep 2013 16:05:20 +0000 (UTC) Received: from [192.168.1.3] (c-98-207-91-59.hsd1.ca.comcast.net [98.207.91.59]) by st11p00mm-asmtp003.mac.com (Oracle Communications Messaging Server 7u4-27.08(7.0.4.27.7) 64bit (built Aug 22 2013)) with ESMTPSA id <0MTL00KIQ3797050@st11p00mm-asmtp003.mac.com>; Mon, 23 Sep 2013 15:04:30 +0000 (GMT) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.10.8794,1.0.431,0.0.0000 definitions=2013-09-23_01:2013-09-22,2013-09-23,1970-01-01 signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 suspectscore=2 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=7.0.1-1308280000 definitions=main-1309230073 User-Agent: Microsoft-MacOutlook/14.3.7.130812 Date: Mon, 23 Sep 2013 08:04:19 -0700 Subject: Re: What's the state of AF-4Kn support? From: Ravi Pokala Sender: Ravi Pokala To: Rozhuk.IM@gmail.com, 'Jia-Shiun Li' Message-id: Thread-topic: What's the state of AF-4Kn support? In-reply-to: <523ff852.4ee8cc0a.44b6.ffffacba@mx.google.com> MIME-version: 1.0 Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7bit X-Mailman-Approved-At: Mon, 23 Sep 2013 16:35:39 +0000 Cc: freebsd-hackers@freebsd.org, freebsd-hardware@freebsd.org X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 23 Sep 2013 16:05:21 -0000 -----Original Message----- From: Reply-To: Date: Monday, September 23, 2013 1:13 AM To: 'Jia-Shiun Li' , Ravi Pokala Cc: , Subject: RE: What's the state of AF-4Kn support? ># install >gpart create -s GPT ada1 >gpart show >gpart add -i 1 -t freebsd-boot -b 40 -s 512 ada1 >gpart add -i 2 -t freebsd-ufs -b 552 -s ..... ada1 >gpart bootcode -b /boot/pmbr ada1 >gpart bootcode -p /boot/gptboot -i 1 ada1 > ># for data >gpart create -s GPT ada1 >gpart show >gpart add -i 1 -t freebsd-ufs -b 40 -s ..... ada1 Thanks Rozhuk, As it happens, I know how to create a GPT table and make sure the partitions are aligned. That's certainly a necessary step for getting good performance on AF-512e drives, but it doesn't have much to do with booting from an AF-4Kn drive. (Actually, since GPT is defined in terms of physical sectors, we can actually *stop* playing silly alignment games with AF-4Kn, since it is inherently aligned.) --rp >> -----Original Message----- >> From: owner-freebsd-hackers@freebsd.org [mailto:owner-freebsd- >> hackers@freebsd.org] On Behalf Of Jia-Shiun Li >> Sent: Monday, September 23, 2013 10:23 AM >> To: Ravi Pokala >> Cc: freebsd-hackers@freebsd.org; freebsd-hardware@freebsd.org >> Subject: Re: What's the state of AF-4Kn support? >> >> On Wed, Sep 18, 2013 at 10:49 PM, Ravi Pokala >> wrote: >> > >> > What you describe is the 'AF-512e' format - 4KB physical sectors >> > *emulating* 512B logical sectors. See [ >> > https://en.wikipedia.org/wiki/Advanced_Format#Advanced_Format_512e ; >> > http://www.idema.org/?page_id=2153 ]. With AF-512e, yes, the HDD >> > firmware does the read/modify/write for I/Os smaller than the >> physical sector size. >> > It is intended to be a low-cost/transitional format, allowing the HDD >> > vendors to get the advantages of 4KB physical sectors (better error >> > detection/correction algorithms, better areal density => lower cost) >> > w/o breaking compatibility with decades of firmware and software that >> > expect 512B logical sectors. >> > >> > What I'm asking about is AF-4kn - 4KB *logical* as well as physical >> > sectors. All the enterprise HDD vendors have told us is that AF-4Kn >> > drives expect data IO to be 4KB, and will reject smaller transfers. >> > (*metadata* IO - SMART, IDENTIFY_DEVICE, READ_LOG/WRITE_LOG, etc - >> > will remain 512B.) >> > >> > Doing some more digging, I found this post from ivoras which I missed >> > the first time around [ >> > http://ivoras.net/blog/tree/2011-01-01.freebsd-on-4k-sector- >> drives.htm >> > l ]; that tends to support my initial assessment - filesystem stuff >> > should Just Work[tm] - plus adds the detail that direct drive I/O >> (the >> > example he gives is trying to `dd' 10 bytes) will be rejected because >> > it is smaller than the raw-device access granularity. I've also >> looked >> > at 'ata_da.c' and see that adaregister() looks at both quirks and >> > IDENTIFY_DEVICE data to determine the logical block size. >> > >> > So, that leaves the bootstrap code as the remaining question-mark. >> > Does anyone what AF-4Kn support looks like there? >> > >> >> CC -hackers. >> >> Thanks for the clarification. Is there any 4Kn HDDs shopping now? I am >> not aware of any. >> >> BTW I believe UFS and ZFS have proper design for 4K-sectors, but >> FreeBSD needs some ecosystem connections to get samples early to test, >> incorporate supports and validate for it. Or we will need to wait until >> it appears on market and someone got caught into some kind of bugs. >> >> Regards, >> Jia-Shiun. >> _______________________________________________ >> freebsd-hackers@freebsd.org mailing list >> http://lists.freebsd.org/mailman/listinfo/freebsd-hackers >> To unsubscribe, send any mail to "freebsd-hackers- >> unsubscribe@freebsd.org" >