From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexandre DERUMIER Subject: Re: block device type supporting trim or scsi unmap ? Date: Thu, 10 May 2012 22:42:02 +0200 (CEST) Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: kvm@vger.kernel.org To: ronnie sahlberg Return-path: Received: from mailpro.odiso.net ([89.248.209.98]:48284 "EHLO mailpro.odiso.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755127Ab2EJUmX convert rfc822-to-8bit (ORCPT ); Thu, 10 May 2012 16:42:23 -0400 In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: >>Guess it depends on how recent kernel your guest runs.=20 >>If you present it as a SCSI disk to the guest, then I have=20 >>successfully had Linux Mint 12 guests do UNMAP when accessing /dev/sd= *=20 >>from within the guest.=20 Ok, thanks for the info, i'll try it ! ----- Mail original -----=20 De: "ronnie sahlberg" =20 =C3=80: "Alexandre DERUMIER" =20 Cc: kvm@vger.kernel.org=20 Envoy=C3=A9: Jeudi 10 Mai 2012 14:36:38=20 Objet: Re: block device type supporting trim or scsi unmap ?=20 On Thu, May 10, 2012 at 10:28 PM, Alexandre DERUMIER=20 wrote:=20 >>>iscsi supports it too but it requires that your iscsi target support= s=20 >>>these opcodes, and that the filesystem/storage behind it supports it= =20 >>>too.=20 >>>TGTD with EXT4 and a suitable storage device should do the trick.=20 >=20 > I'm using a iscsi solaris target, with scsi UNMAP support.=20 > Drives also support scsi unmap in raid (ocz talos hdd).=20 > I'm using direct lun access from host to guest.=20 >=20 >=20 > But my question was, which block device inside guests have trim or sc= si unmap implemention ?=20 >=20 >=20 Guess it depends on how recent kernel your guest runs.=20 If you present it as a SCSI disk to the guest, then I have=20 successfully had Linux Mint 12 guests do UNMAP when accessing /dev/sd*=20 from within the guest.=20 If you present the device as a SCSI disk to the guest, you use a=20 recent 3.x linux kernel for the guest and EXT4 as the filesystem=20 I guess it should work.=20 Dont know about status for IDE emulation.=20 regards=20 ronnie sahlberg=20 --=20 --=20 Alexandre D erumier=20 Ing=C3=A9nieur Syst=C3=A8me=20 =46ixe : 03 20 68 88 90=20 =46ax : 03 20 68 90 81=20 45 Bvd du G=C3=A9n=C3=A9ral Leclerc 59100 Roubaix - France=20 12 rue Marivaux 75002 Paris - France=20 =09