From mboxrd@z Thu Jan 1 00:00:00 1970
Return-Path: <pve-devel-bounces@lists.proxmox.com>
Received: from firstgate.proxmox.com (firstgate.proxmox.com [IPv6:2a01:7e0:0:424::9])
by lore.proxmox.com (Postfix) with ESMTPS id 96B1E1FF16B
for <inbox@lore.proxmox.com>; Thu, 9 Jan 2025 14:20:35 +0100 (CET)
Received: from firstgate.proxmox.com (localhost [127.0.0.1])
by firstgate.proxmox.com (Proxmox) with ESMTP id A4BC6F29B;
Thu, 9 Jan 2025 14:20:20 +0100 (CET)
Date: Thu, 9 Jan 2025 14:19:38 +0100
To: Proxmox VE development discussion <pve-devel@lists.proxmox.com>,
=?UTF-8?Q?Fabian_Gr=C3=BCnbichler?= <f.gruenbichler@proxmox.com>
References: <20241216091229.3142660-1-alexandre.derumier@groupe-cyllene.com>
<mailman.210.1734340371.332.pve-devel@lists.proxmox.com>
<570013533.830.1736423850641@webmail.proxmox.com>
In-Reply-To: <570013533.830.1736423850641@webmail.proxmox.com>
MIME-Version: 1.0
Message-ID: <mailman.172.1736428820.441.pve-devel@lists.proxmox.com>
List-Id: Proxmox VE development discussion <pve-devel.lists.proxmox.com>
List-Post: <mailto:pve-devel@lists.proxmox.com>
From: Fabio Fantoni via pve-devel <pve-devel@lists.proxmox.com>
Precedence: list
Cc: Fabio Fantoni <fabio.fantoni@m2r.biz>
X-Mailman-Version: 2.1.29
X-BeenThere: pve-devel@lists.proxmox.com
List-Subscribe: <https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel>,
<mailto:pve-devel-request@lists.proxmox.com?subject=subscribe>
List-Unsubscribe: <https://lists.proxmox.com/cgi-bin/mailman/options/pve-devel>,
<mailto:pve-devel-request@lists.proxmox.com?subject=unsubscribe>
List-Archive: <http://lists.proxmox.com/pipermail/pve-devel/>
Reply-To: Proxmox VE development discussion <pve-devel@lists.proxmox.com>
List-Help: <mailto:pve-devel-request@lists.proxmox.com?subject=help>
Subject: Re: [pve-devel] [PATCH v3 qemu-server 11/11] qcow2: add external
snapshot support
Content-Type: multipart/mixed; boundary="===============0134017791333959120=="
Errors-To: pve-devel-bounces@lists.proxmox.com
Sender: "pve-devel" <pve-devel-bounces@lists.proxmox.com>
--===============0134017791333959120==
Content-Type: message/rfc822
Content-Disposition: inline
Return-Path: <fabio.fantoni@m2r.biz>
X-Original-To: pve-devel@lists.proxmox.com
Delivered-To: pve-devel@lists.proxmox.com
Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68])
(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)
key-exchange X25519 server-signature RSA-PSS (2048 bits))
(No client certificate requested)
by lists.proxmox.com (Postfix) with ESMTPS id 13F45CB629
for <pve-devel@lists.proxmox.com>; Thu, 9 Jan 2025 14:20:19 +0100 (CET)
Received: from firstgate.proxmox.com (localhost [127.0.0.1])
by firstgate.proxmox.com (Proxmox) with ESMTP id E5D46F1D6
for <pve-devel@lists.proxmox.com>; Thu, 9 Jan 2025 14:19:48 +0100 (CET)
Received: from mail-ej1-x633.google.com (mail-ej1-x633.google.com [IPv6:2a00:1450:4864:20::633])
(using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits)
key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256)
(No client certificate requested)
by firstgate.proxmox.com (Proxmox) with ESMTPS
for <pve-devel@lists.proxmox.com>; Thu, 9 Jan 2025 14:19:48 +0100 (CET)
Received: by mail-ej1-x633.google.com with SMTP id a640c23a62f3a-aaf900cc7fbso187519366b.3
for <pve-devel@lists.proxmox.com>; Thu, 09 Jan 2025 05:19:48 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
d=m2r-biz.20230601.gappssmtp.com; s=20230601; t=1736428782; x=1737033582; darn=lists.proxmox.com;
h=content-transfer-encoding:in-reply-to:from:content-language
:references:to:subject:user-agent:mime-version:date:message-id:from
:to:cc:subject:date:message-id:reply-to;
bh=3EjqcveyufzAcLHi2OqcBPvt2GB6JS5mw7B1BC8TsOY=;
b=08DDxneKGDlMk3vhqVk2l5L0ycFuK0jA9PsbajSOiHEWgEQnUpKEWl4SZf3WWTdesj
ZB975r/FIFLc7qjBnDI/vlF6LaIzqh3j/H4UIOBxPRBkuIMU4En1HIic+HGsamAbs/1L
iA1ln7kwzQHzkUq3CffO+mR9aWo9fe/itTUNKotc7CAg0hGqlwPuwoT4WqIbsZIeogMv
pKlSs7ffR03fIaFgTxY+qrSZFjixgopAm5oHNgfo98jX4bm5IHC1AN1lzYguOsG7MH0z
bOwOHQuzWmSr8w7FuTkuD2XKO5G7EpX8r+7KwWRT7+Y0aOyDMKgSN+x+z+v83oNYmqpq
N5Cw==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
d=1e100.net; s=20230601; t=1736428782; x=1737033582;
h=content-transfer-encoding:in-reply-to:from:content-language
:references:to:subject:user-agent:mime-version:date:message-id
:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to;
bh=3EjqcveyufzAcLHi2OqcBPvt2GB6JS5mw7B1BC8TsOY=;
b=ZT3UKiE2tLuZIW3d77S9mytxX83MyzRGq8VL44nATwDNCkrIon5rJme0lUG7fTE3dZ
KQz+ihtbPCfjWn7t3fnk7j7b5LmGirCd3zSFHDHDh+Cl78zM6d4051Cq9m/q8AcBZaHw
p1VIA076gjZSHvbn7+dZ6zlB+jKxxsf6jQSGKjnO7l2slB70Zqbz7mdiJRMPufSz7YdD
eikV8PBALAMyB1yaRRifdLYq5R4ZXrBz9D5yYj4+WQ7Z9z12i5CLk6tFNUyvqlQbVObN
93XAKjCr9RdpEn+nDkKDuQSHBQZ8yTxNpvAoDOKa+ZaFTYz2nOjSeqDkaZ7LXr0ef1GP
yxsg==
X-Gm-Message-State: AOJu0YwvGRZnIuWwzkprPU6eUAYrKGCyjmzECzffaqU9bschhMuyF2W8
acbjcRhjXz83vWz9a7Vm4kupNNa/B4+Hswo9RROhsYyXeCu7zXJClE0asDB5LSXCfdST+zeaZ2O
/
X-Gm-Gg: ASbGncu6q7vA6/KX3z1fF1xiCTx9G43+B65AkE9DZZX4sNVv/nGxiRqb24tSO2j4fUw
Ynb5z0wl6IidSB8vJGoeRspOCM5XWAwlXIj2BGTv019wCinwopg439wVCrY5vHzqiWNz8yKkvJp
uyGoeAbcMz053m9QgzfVp2SxEWHUEOF1+/kl2VwdwetxOXqqhBjFLRpUHsjDGBDyNKNOLf7cHYn
ZCFJGqW7c2RqEcmcrwqXeQhLW34GDASTlOxmDXLBPkvY6EAOe7O2OCV3V0V6r0OZBiNoTbqn2mn
ZuhSK95PdR0kbzzQbyfOAozmF9dPgzo2vQ+QjYOdVQ==
X-Google-Smtp-Source: AGHT+IGU2wNgL0dmtOIE5Y6Re3Ix24XtDEbCqhUDufogr3Iw8WuCyasBF4wGvZKyvC9Hzc3yip+aCg==
X-Received: by 2002:a17:907:7286:b0:aae:f645:8ba4 with SMTP id a640c23a62f3a-ab2ab6bfa23mr469116566b.9.1736428781717;
Thu, 09 Jan 2025 05:19:41 -0800 (PST)
Received: from [192.168.178.27] (host-87-0-86-235.retail.telecomitalia.it. [87.0.86.235])
by smtp.googlemail.com with ESMTPSA id a640c23a62f3a-ab2c9060db6sm72320366b.8.2025.01.09.05.19.40
(version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256);
Thu, 09 Jan 2025 05:19:41 -0800 (PST)
Message-ID: <483058af-44d9-441c-98df-fd7150184ebe@m2r.biz>
Date: Thu, 9 Jan 2025 14:19:38 +0100
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [pve-devel] [PATCH v3 qemu-server 11/11] qcow2: add external
snapshot support
To: Proxmox VE development discussion <pve-devel@lists.proxmox.com>,
=?UTF-8?Q?Fabian_Gr=C3=BCnbichler?= <f.gruenbichler@proxmox.com>
References: <20241216091229.3142660-1-alexandre.derumier@groupe-cyllene.com>
<mailman.210.1734340371.332.pve-devel@lists.proxmox.com>
<570013533.830.1736423850641@webmail.proxmox.com>
Content-Language: it
From: Fabio Fantoni <fabio.fantoni@m2r.biz>
In-Reply-To: <570013533.830.1736423850641@webmail.proxmox.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
X-Antivirus: Avast (VPS 250109-2, 9/1/2025), Outbound message
X-Antivirus-Status: Clean
X-SPAM-LEVEL: Spam detection results: 0
BAYES_00 -1.9 Bayes spam probability is 0 to 1%
DKIM_SIGNED 0.1 Message has a DKIM or DK signature, not necessarily valid
DKIM_VALID -0.1 Message has at least one valid DKIM or DK signature
DMARC_PASS -0.1 DMARC pass policy
JMQ_SPF_NEUTRAL 0.5 SPF set to ?all
KAM_INFOUSMEBIZ 0.75 Prevalent use of .info|.us|.me|.me.uk|.biz|xyz|id|rocks|life domains in spam/malware
RCVD_IN_DNSWL_NONE -0.0001 Sender listed at https://www.dnswl.org/, no trust
SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record
SPF_PASS -0.001 SPF: sender matches SPF record
Il 09/01/2025 12:57, Fabian Grünbichler ha scritto:
>> Alexandre Derumier via pve-devel <pve-devel@lists.proxmox.com> hat am 16.12.2024 10:12 CET geschrieben:
> it would be great if there'd be a summary of the design choices and a high level summary of what happens to the files and block-node-graph here. it's a bit hard to judge from the code below whether it would be possible to eliminate the dynamically named block nodes, for example ;)
>
> a few more comments documenting the behaviour and ideally also some tests (mocking the QMP interactions?) would be nice
@Alexandre Derumier: Thanks for add external snapshot support, I have
not looked at the implementation in detail because I do not have enough
time but I think external snapshot support would be useful.
I used it outside of proxmox years ago, on Debian servers with VMs
managed with libvirt, I managed external snapshots completely manually
from cli with multiple commands because they were not implemented in
virtmanager and they were useful to save a lot of time (instead of
backup/restore) in some high-risk operations on VMs with large disks,
raw pre-allocated on hdd disks.
I used them very little and kept them only the minimum time necessary
for delicate maintenance operations, if there were unforeseen events it
returned to the situation before the snapshot, I deleted the external
snapshot and created another one to try again, if instead everything was
ok in the end I did the commit, and went back to using only the
pre-allocated raw image. With high disk usage as in the operations I was
doing the performance decrease with external qcow2 snapshots compared to
just pre-allocated raw disks was huge if I remember correctly (which is
why I used them for the minimum amount of time possible).
If it hasn't already been planned I think it could be useful to warn
users (atleast in documentation) to avoid them underestimating their
possible impact on performance (especially if they basically have
pre-allocated raw on hdd disks for greater performance and minimal
defragmentation) and avoid use or keep them for a long time without real
need. Another important thing to notify users is the increase in space
usage (again mainly for those who are used to pre-allocated disks where
they usually don't risk increases in space).
In this implementation I don't see the possibility of using them on raw
disks (on files) from a fast look, or am I wrong? If so, why? I think
the main use would be in cases like that where you don't have snapshot
support by default
--
Questa email è stata esaminata alla ricerca di virus dal software antivirus Avast.
www.avast.com
--===============0134017791333959120==
Content-Type: text/plain; charset="us-ascii"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
_______________________________________________
pve-devel mailing list
pve-devel@lists.proxmox.com
https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
--===============0134017791333959120==--