From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <pbs-devel-bounces@lists.proxmox.com> Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68]) by lore.proxmox.com (Postfix) with ESMTPS id 890641FF176 for <inbox@lore.proxmox.com>; Fri, 7 Mar 2025 10:33:56 +0100 (CET) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 1E53916E59; Fri, 7 Mar 2025 10:33:51 +0100 (CET) From: Dominik Csapak <d.csapak@proxmox.com> To: pbs-devel@lists.proxmox.com Date: Fri, 7 Mar 2025 10:33:48 +0100 Message-Id: <20250307093348.1093008-1-d.csapak@proxmox.com> X-Mailer: git-send-email 2.39.5 MIME-Version: 1.0 X-SPAM-LEVEL: Spam detection results: 0 AWL 0.022 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% DMARC_MISSING 0.1 Missing DMARC policy KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment RCVD_IN_VALIDITY_CERTIFIED_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to Validity was blocked. See https://knowledge.validity.com/hc/en-us/articles/20961730681243 for more information. RCVD_IN_VALIDITY_RPBL_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to Validity was blocked. See https://knowledge.validity.com/hc/en-us/articles/20961730681243 for more information. RCVD_IN_VALIDITY_SAFE_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to Validity was blocked. See https://knowledge.validity.com/hc/en-us/articles/20961730681243 for more information. SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record Subject: [pbs-devel] [PATCH proxmox-backup] docs: fix hash collision probability comparison X-BeenThere: pbs-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox Backup Server development discussion <pbs-devel.lists.proxmox.com> List-Unsubscribe: <https://lists.proxmox.com/cgi-bin/mailman/options/pbs-devel>, <mailto:pbs-devel-request@lists.proxmox.com?subject=unsubscribe> List-Archive: <http://lists.proxmox.com/pipermail/pbs-devel/> List-Post: <mailto:pbs-devel@lists.proxmox.com> List-Help: <mailto:pbs-devel-request@lists.proxmox.com?subject=help> List-Subscribe: <https://lists.proxmox.com/cgi-bin/mailman/listinfo/pbs-devel>, <mailto:pbs-devel-request@lists.proxmox.com?subject=subscribe> Reply-To: Proxmox Backup Server development discussion <pbs-devel@lists.proxmox.com> Cc: t.lamprecht@proxmox.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: pbs-devel-bounces@lists.proxmox.com Sender: "pbs-devel" <pbs-devel-bounces@lists.proxmox.com> Commit: efc09f63c (docs: tech overview: avoid 'we' and other small style fixes/additions) introduced the comparison with 13 lottery games, but sadly without any mention how to arrive at that number. When calculating I did arrive at 8-9 games (8 is more probable, 9 is less probable), so rewrite to 'chance is lower than 8 lottery games' and give the calculation directly inline as a reference. Suggested-by: Dietmar Maurer <dietmar@proxmox.com> Signed-off-by: Dominik Csapak <d.csapak@proxmox.com> --- @Thomas: if you can remember how we arrived at the '13' all those years ago, we could check if that calculation makes more sense than what I'm doing here, and rererence it? docs/technical-overview.rst | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/docs/technical-overview.rst b/docs/technical-overview.rst index 6a76942f1..fdeb3a093 100644 --- a/docs/technical-overview.rst +++ b/docs/technical-overview.rst @@ -298,8 +298,8 @@ will see that the probability of a collision in that scenario is: For context, in a lottery game of guessing 6 numbers out of 45, the chance to correctly guess all 6 numbers is only :math:`1.2277 * 10^{-7}`. This means the -chance of a collision is about the same as winning 13 such lottery games *in a -row*. +chance of a collision is lower than winning 8 such lottery games *in a row*: +:math:`(1.2277 * 10^{-7})^{8} = 5.1623 * 10^{-56}`. In conclusion, it is extremely unlikely that such a collision would occur by accident in a normal datastore. -- 2.39.5 _______________________________________________ pbs-devel mailing list pbs-devel@lists.proxmox.com https://lists.proxmox.com/cgi-bin/mailman/listinfo/pbs-devel