From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mats Petersson Subject: Re: !!!!!help!I wouldn't be able to meet the deadline!(qcow format image file read operation in qemu-img-xen)[updated] Date: Wed, 19 Dec 2012 15:32:41 +0000 Message-ID: <50D1DE19.1080709@citrix.com> References: <2cff694b.c956.13bb3c38014.Coremail.hxkhust@126.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <2cff694b.c956.13bb3c38014.Coremail.hxkhust@126.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On 19/12/12 15:23, hxkhust wrote: > Or could you tell me how to cache the data which is read from the > backingfile when a qcow image is regarded as a virtual disk in a > running HVM? I take it the above single question is the effect of my previous reply? Why did you have to "hide" that little extra question in the whole previous e-mail? Sorry, don't know the answer to your question [I'm guessing, in general, that the Dom0 will do that for you, subject to available space], just pointing out that there is a minor difference between your previous and current mail. By caching, do you mean "load the entire file into RAM", or "if a read is requested for the same piece of 'disk' multiple times, I want the previous result to be stored and returned". -- Mats