From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: 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 537CA64D71 for ; Tue, 21 Jul 2020 11:55:09 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 4B31B16F7D for ; Tue, 21 Jul 2020 11:54:39 +0200 (CEST) Received: from proxmox-new.maurer-it.com (proxmox-new.maurer-it.com [212.186.127.180]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by firstgate.proxmox.com (Proxmox) with ESMTPS id 4D84D16F65 for ; Tue, 21 Jul 2020 11:54:38 +0200 (CEST) Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id 1996843300 for ; Tue, 21 Jul 2020 11:54:38 +0200 (CEST) From: Aaron Lauterer To: pbs-devel@lists.proxmox.com Date: Tue, 21 Jul 2020 11:54:35 +0200 Message-Id: <20200721095437.10316-1-a.lauterer@proxmox.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SPAM-LEVEL: Spam detection results: 0 AWL -0.000 Adjusted score from AWL reputation of From: address KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment RCVD_IN_DNSWL_MED -2.3 Sender listed at https://www.dnswl.org/, medium trust 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 1/3] docs: fix #2851 Add note about GC grace period X-BeenThere: pbs-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox Backup Server development discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 21 Jul 2020 09:55:09 -0000 Adding a note about the garbage collection's grace period due to the default atime behavior should help to avoid confusion as to why space is not freed immediately. Signed-off-by: Aaron Lauterer --- I hope I got the technical details right. I did put the section in a note for now but I am not sure if it is the best way to present that information. docs/administration-guide.rst | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/docs/administration-guide.rst b/docs/administration-guide.rst index 254d36e1..a0ac8c79 100644 --- a/docs/administration-guide.rst +++ b/docs/administration-guide.rst @@ -962,6 +962,17 @@ unused data blocks are removed. depending on the number of chunks and the speed of the underlying disks. +.. note:: The garbage collection will only remove chunks that haven't been used + for at least one day (exactly 24h 5m). This grace period is necessary because + chunks in use are marked by touching the chunk which updates the ``atime`` + (access time) property. Filesystems are mounted with the ``relatime`` option + by default. This results in a better performance by only updating the + ``atime`` property if the last access has been at least 24 hours ago. The + downside is, that touching a chunk within these 24 hours will not update its + ``atime`` property. + + If there are chunks in the grace period, it will be logged at the end of the + garbage collection run as *Pending removals*. .. code-block:: console -- 2.20.1