From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Prof. Dr. Klaus Kusche" Subject: Re: Good SAS adapters for 6 Gb/s SATA SSD's (with TRIM)? Date: Fri, 12 Aug 2011 10:04:30 +0200 Message-ID: <4E44DE8E.3070809@computerix.info> References: <4E43F2C3.9000808@computerix.info> <4E4434A4.7010808@interlog.com> <4E449BB1.3060300@interlog.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from www74.your-server.de ([213.133.104.74]:35008 "EHLO www74.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750791Ab1HLIEi (ORCPT ); Fri, 12 Aug 2011 04:04:38 -0400 In-Reply-To: <4E449BB1.3060300@interlog.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: dgilbert@interlog.com Cc: linux-scsi@vger.kernel.org On 2011-08-12 05:19, Douglas Gilbert wrote: > On 11-08-11 03:59 PM, Douglas Gilbert wrote: >> On 11-08-11 11:18 AM, Prof. Dr. Klaus Kusche wrote: >>> I'm looking for ways to hook up fast 6 Gb/s SATA SSD's (non-RAID!) >>> to (server or i-X58) mainboards which do not have native 6 Gb/s SAT= A. >>> >>> From the reviews I've read so far, two things became obvious: >>> * The SSD's I'm looking at really want a working SATA TRIM command. >>> * All the onboard Marvell 88SE9128 (or ASmedia) solutions >>> seriuosly lack performance, as do PCIe cards based on those chips. >>> >>> So basically, there seem to be two choices: >>> 1.) LSI 2008 >>> 2.) Marvell 9485 >>> >>> 1.) seems to be fast, reliable and well-supported, >>> but as far as I can tell, it doesn't support TRIM at all: >>> It neither maps SCSI unmap to SATA TRIM, >>> nor accepts TRIM as a SATA passthrough command. >>> >>> Is that true? >> >> What counts in Linux for "trim" support on a SSD (SATA, >> SAS or FC) is correctly processing the SCSI WRITE SAME (16) >> with the UNMAP bit set. In the case of a SATA SSD, a SCSI >> to ATA Translation Layer (SATL) should map that SCSI WRITE >> SAME (16) with the UNMAP bit set to the ATA DATA SET >> MANAGEMENT command with the TRIM attribute set. >> >> Many Linux SATA low level drivers use libata which >> implements the above mapping. However some SAS HBAs >> (e.g. LSI MPT Fusion 3 and 6 Gbps) implement the SATL >> in their own HBA firmware. >> >> I tested a LSI SAS 9212-4i4e HBA running its most recent >> firmware (9.0 from Feb 26, 2011) with a Intel SSDSA2M080 >> which does support trim. I used my ddpt utility and the >> SCSI WRITE SAME (16) with the UNMAP bit set was rejected >> as an "illegal request". With the UNMAP bit clear it >> accepted the command. I also checked the SCSI UNMAP >> command and it was also rejected. >> >> LSI have some more work to do on their firmware. > > I did check the LSI support page for my HBA just before sending > my original reply. And the version 9 firmware was showing at the > top of the list. Alas, that page had been alpha sorted on the > file names so that version 10 of the firmware (May 2011) was > hiding further down the page :-) > > So I installed the newest firmware and redid the above tests. > Now the SCSI WRITE SAME (16) with the UNMAP bit set works on > that SSD. The SCSI UNMAP command was rejected and I did not > test sending the ATA DATA SET MANAGEMENT command through > the pass-through (but I expect that would work). > > So Linux file systems will be able "discard" (=3D"unmap"(SCSI); > =3D"trim"(ATA)) data using LSI HBAs based the LSI 2008 chip > which are running recent firmware. Was that with the RAID or the non-RAID firmware? I've asked LSI sales/support about UNMAP/TRIM being supported. They've opened a case, but I got zero response up to now. So it doesn't seem to be on the official feature list, and it seems to be unknown at least in the Munich LSI office. Am I correct that this would support online trimming (mount discard), but not batch trimming with wiper.sh or similar tools/scripts, because they issue TRIM or UNMAP directly, not WRITE SAME UNMAP? (what's the SCSI equivalent to the wiper.sh script?) Nobody having any info's about Marvell / mvsas? Klaus. --=20 Prof. Dr. Klaus Kusche Private address: Rainstra=DFe 9/1, 88316 Isny, Germany +49 7562 6211377 Klaus.Kusche@computerix.info http://www.computerix.inf= o Office address: NTA Isny gGmbH, Seidenstra=DFe 12-35, 88316 Isny, Germa= ny +49 7562 9707 36 kusche@nta-isny.de http://www.nta-isny.de -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html