From: Stefan Hajnoczi <stefanha@redhat.com>
To: "Benoît Canet" <benoit.canet@irqsave.net>
Cc: kwolf@redhat.com, Stefan Hajnoczi <stefanha@gmail.com>,
qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [RFC V3 01/24] qcow2: Add deduplication to the qcow2 specification.
Date: Tue, 18 Dec 2012 14:38:06 +0100 [thread overview]
Message-ID: <20121218133806.GA6697@stefanha-thinkpad.redhat.com> (raw)
In-Reply-To: <20121212155737.GA3478@irqsave.net>
On Wed, Dec 12, 2012 at 04:57:38PM +0100, Benoît Canet wrote:
> > Can you foresee the need to use a different hash algorithm in the future
> > and should we add a hash_algo enum field to the dedup QCOW2 header
> > extension?
>
> Yes I foresee the future use of faster hash function like SHA3 or Skein.
>
> I also think an alternate deduplication mechanism where lookups are done
> on disk in order to be able to deduplicate very large volume could be added.
>
> What would be the cleanest way to store this in the header extension ?
> bitmaps or two char fields ?
The header extension could have a uint8_t hash_algo field (and 3
reserved bytes that can be used in the future).
0 - SHA256
1 - Skein
...
Stefan
next prev parent reply other threads:[~2012-12-18 13:38 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-26 13:04 [Qemu-devel] [RFC V3 00/24] QCOW2 deduplication Benoît Canet
2012-11-26 13:05 ` [Qemu-devel] [RFC V3 01/24] qcow2: Add deduplication to the qcow2 specification Benoît Canet
2012-12-11 11:28 ` Stefan Hajnoczi
2012-12-11 11:32 ` Stefan Hajnoczi
2012-12-12 15:57 ` Benoît Canet
2012-12-18 13:38 ` Stefan Hajnoczi [this message]
2012-12-11 23:03 ` Eric Blake
2012-12-12 15:59 ` Benoît Canet
2012-11-26 13:05 ` [Qemu-devel] [RFC V3 02/24] qcow2: Add deduplication structures and fields Benoît Canet
2012-12-11 11:34 ` Stefan Hajnoczi
2012-11-26 13:05 ` [Qemu-devel] [RFC V3 03/24] qcow2: Add qcow2_dedup_read_missing_and_concatenate Benoît Canet
2012-12-11 11:52 ` Stefan Hajnoczi
2012-11-26 13:05 ` [Qemu-devel] [RFC V3 04/24] qcow2: Make update_cluster_refcount public Benoît Canet
2012-11-26 13:05 ` [Qemu-devel] [RFC V3 05/24] qcow2: Create a way to link to l2 tables in dedup Benoît Canet
2012-11-26 13:05 ` [Qemu-devel] [RFC V3 06/24] qcow2: Add qcow2_dedup and related functions Benoît Canet
2012-12-11 13:16 ` Stefan Hajnoczi
2012-11-26 13:05 ` [Qemu-devel] [RFC V3 07/24] qcow2: Add qcow2_dedup_write_new_hashes Benoît Canet
2012-11-26 13:05 ` [Qemu-devel] [RFC V3 08/24] qcow2: Implement qcow2_compute_cluster_hash Benoît Canet
2012-12-11 13:28 ` Stefan Hajnoczi
2012-11-26 13:05 ` [Qemu-devel] [RFC V3 09/24] qcow2: Extract qcow2_dedup_grow_table Benoît Canet
2012-11-26 13:05 ` [Qemu-devel] [RFC V3 10/24] qcow2: create function to load deduplication hashes at startup Benoît Canet
2012-11-26 13:05 ` [Qemu-devel] [RFC V3 11/24] qcow2: Load and save deduplication table header extension Benoît Canet
2012-11-26 13:05 ` [Qemu-devel] [RFC V3 12/24] qcow2: Extract qcow2_do_table_init Benoît Canet
2012-11-26 13:05 ` [Qemu-devel] [RFC V3 13/24] qcow2: Add qcow2_dedup_init and qcow2_dedup_close Benoît Canet
2012-11-26 13:05 ` [Qemu-devel] [RFC V3 14/24] qcow2: Extract qcow2_add_feature and qcow2_remove_feature Benoît Canet
2012-11-26 13:05 ` [Qemu-devel] [RFC V3 15/24] block: Add dedup image create option Benoît Canet
2012-11-26 13:05 ` [Qemu-devel] [RFC V3 16/24] qcow2: Allow creation of images using deduplication Benoît Canet
2012-11-26 13:05 ` [Qemu-devel] [RFC V3 17/24] qcow2: Behave correctly when refcount reach 0 or 2^16 Benoît Canet
2012-11-26 13:05 ` [Qemu-devel] [RFC V3 18/24] qcow2: Integrate deduplication in qcow2_co_writev loop Benoît Canet
2012-11-26 13:05 ` [Qemu-devel] [RFC V3 19/24] qcow2: Add verification of dedup table Benoît Canet
2012-11-26 13:05 ` [Qemu-devel] [RFC V3 20/24] qcow2: Adapt checking of QCOW_OFLAG_COPIED for dedup Benoît Canet
2012-11-26 13:05 ` [Qemu-devel] [RFC V3 21/24] qcow2: Add check_dedup_l2 in order to check l2 of dedup table Benoît Canet
2012-11-26 13:05 ` [Qemu-devel] [RFC V3 22/24] qcow2: Do not overwrite existing entries with QCOW_OFLAG_COPIED Benoît Canet
2012-11-26 13:05 ` [Qemu-devel] [RFC V3 23/24] qcow2: init and cleanup deduplication Benoît Canet
2012-11-26 13:05 ` [Qemu-devel] [RFC V3 24/24] qemu-iotests: Filter dedup=on/off so existing tests don't break Benoît Canet
2012-12-11 14:19 ` [Qemu-devel] [RFC V3 00/24] QCOW2 deduplication Stefan Hajnoczi
2012-12-11 14:38 ` Stefan Hajnoczi
2012-12-12 16:14 ` Benoît Canet
2012-12-18 13:42 ` Stefan Hajnoczi
2012-12-24 12:26 ` Benoît Canet
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