From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tim Deegan Subject: Re: Domain Save Image Format proposal (draft B) Date: Wed, 12 Feb 2014 16:34:40 +0100 Message-ID: <20140212153440.GC91459@deinos.phlegethon.org> References: <52F90A71.40802@citrix.com> <52F97E6F.2000402@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Shriram Rajagopalan Cc: Ian Campbell , Stefano Stabellini , Andrew Cooper , Ian Jackson , "Xen-devel@lists.xen.org" , David Vrabel List-Id: xen-devel@lists.xenproject.org At 22:12 -0600 on 10 Feb (1392066773), Shriram Rajagopalan wrote: > My point here being, checksums seem like unnecessary compute overhead when > doing live migration > or Remus. One can simply set this field to 0 when doing live > migration/Remus. Remus _compresses_ the payload, right? CRC32 is basically free compared to that. But I think the point about checksumming the whole image is sound. That will catch _more_ classes of corruption than a per-block data checksum, and the class of bugs caught by per-block checksums (basically, that the header and the data don't match for some reason) are pretty small in this design. Tim.