From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1FeZyC-0005zB-RG for qemu-devel@nongnu.org; Fri, 12 May 2006 11:54:24 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1FeZyB-0005yx-7I for qemu-devel@nongnu.org; Fri, 12 May 2006 11:54:24 -0400 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1FeZyB-0005yt-16 for qemu-devel@nongnu.org; Fri, 12 May 2006 11:54:23 -0400 Received: from [24.215.0.11] (helo=ns1.mountaincable.net) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA:32) (Exim 4.52) id 1FeZzw-0003QW-2f for qemu-devel@nongnu.org; Fri, 12 May 2006 11:56:12 -0400 Received: from copacetic.desrt.ca (unknown [71.19.9.154]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ns1.mountaincable.net (Postfix) with ESMTP id 11F70140ED for ; Fri, 12 May 2006 11:54:21 -0400 (EDT) Received: from moonpix.desrt.ca (moonpix.desrt.ca [172.16.0.2]) by copacetic.desrt.ca (8.13.4/8.13.4) with ESMTP id k4CFsGiU044400 for ; Fri, 12 May 2006 11:54:16 -0400 (EDT) (envelope-from desrt@desrt.ca) Subject: Re: [Qemu-devel] PATCH: Support for multi-file raw images From: Ryan Lortie In-Reply-To: <20060512143517.GL15855@narn.hozed.org> References: <1147329045.17542.15.camel@moonpix.desrt.ca> <20060512143517.GL15855@narn.hozed.org> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-KMRnkNUja5wT32r99ST0" Date: Fri, 12 May 2006 11:54:16 -0400 Message-Id: <1147449256.32254.4.camel@moonpix.desrt.ca> Mime-Version: 1.0 Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org --=-KMRnkNUja5wT32r99ST0 Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Fri, 2006-12-05 at 09:35 -0500, Troy Benjegerdes wrote: > Have you tried making a read-only 'base' image and using qcow images > instead? I'm not convinced that splitting things up is going to help a > lot. You might end up writing 1 512 byte block each to 500 files.. in > the qcow image case, that is writing 256K, and with 10mb files, that's > 5GB. The problem with this approach is that I get an ever-growing changes file which must eventually be merged (and then I have to copy the 20GB again). > at the very least, the console should print an error. If you can keep > all the files open, deleting the file won't be a problem. I agree -- console error should definitely occur. Opening all the files at the start is something to consider. It does fly in the face of two things, though: 1 -- Limiting the number of fds. Obviously opening all file parts at the very start will use up a whack of fds right away. 2 -- Not modifying files that haven't been modified. If you open a file read-write then its modification time is automatically updated and rsync will want to checksum/copy it again (it quickly checks local files based on modtime and size). If you open all files read-only then the file may not be there when you go to reopen it read-write. This is why the current implementation is as lazy as possible in terms of opening files. Cheers --=-KMRnkNUja5wT32r99ST0 Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2.2 (GNU/Linux) iQG5AwUARGSvqJ96IjKvqm/2AQLTUw0feRE2XSAEv2GtMVcWfJ2Y2EjXINqYygij J6mfWgt7dv7EkgEtmC8jnCkUIVNNQwENX3gkM5hBBFpu/C8m5vBX+HYn3LAvddvS aNircMP2/alHYQlceIW1CUxmo7LxN8FXWbxUYj6p4VOO3i97JljuBesl4gRv6KlQ SNa/SWldecyToboqvgwO6R3TEbRc+pDrzrm0ko02DoFT3Yle5DK01T2cNkRzPm3y D5SqLVPXd5e3NCJQPVyn+5nYauvkR+Q8mZp0lCpZOwlEpNyoeHgD/iWRyw0X7k6P mm+s/f6/1UnY6w7Gi91QbvVsirVu8Y+6ILCjwhwAwH7or1rCt01Ct2c2siMwmBo+ C8JcmeF6XmkZfeb8/6Nc+kKE7zbaZNNQe7oHzuSSdKxhXmfw1u5NgC1S05ax/Gtg endKca9pzePnH07MvnWM0R9y1zF1ABhbOFRiABrHgY1pCEAoR5I4o82TMJiEanDU OlokWXLIeWf5Qcqe7s2bEdckJA6fRz2xOy2oc7YphPcoLZtM8FKQVZkXYCMK1paM kUoTXwmLNyawLHOd =pvWw -----END PGP SIGNATURE----- --=-KMRnkNUja5wT32r99ST0--