From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: Fwd: Discard is not working Date: Fri, 07 Feb 2014 22:07:44 +0100 Message-ID: <52F54B20.6030305@redhat.com> References: <52F2C104.4040503@freenet.de> <52F422C2.9020509@redhat.com> <52F50BA3.10309@msgid.tls.msk.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Cc: KVM list , chickenmarkus@freenet.de To: Michael Tokarev , unlisted-recipients:; Return-path: Received: from mail-ea0-f172.google.com ([209.85.215.172]:56704 "EHLO mail-ea0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751768AbaBGVHv (ORCPT ); Fri, 7 Feb 2014 16:07:51 -0500 Received: by mail-ea0-f172.google.com with SMTP id l9so1537663eaj.3 for ; Fri, 07 Feb 2014 13:07:50 -0800 (PST) In-Reply-To: <52F50BA3.10309@msgid.tls.msk.ru> Sender: kvm-owner@vger.kernel.org List-ID: Il 07/02/2014 17:36, Michael Tokarev ha scritto: > However, when I export the same test.raw file using virtio, like this: > > -drive file=test.raw,if=virtio,discard=unmap > > it doesn't work: guest does not see the virtio drive as discardable. > >> > Did I understand something wrong? Is the command wrong? Are any >> > requirements not met? > So I've no idea what's going on here... ;) Thanks Michael for the experiments! I missed this email. virtio-blk does not support discard, so this is expected. Regarding lsblk -D, DISC-ZERO is never true in VMs (not yet at least!), but the important one is DISC-GRAN. Paolo