From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [IPv6:2a01:7e0:0:424::9]) by lore.proxmox.com (Postfix) with ESMTPS id 16ADE1FF13B for ; Wed, 25 Mar 2026 08:09:22 +0100 (CET) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 341BC9976; Wed, 25 Mar 2026 08:09:43 +0100 (CET) Message-ID: Date: Wed, 25 Mar 2026 08:09:08 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Beta Subject: Re: [RFC proxmox{,-backup} 0/6] add scheduled fstrim job for datastore's backing filesystems To: Christian Ebner , pbs-devel@lists.proxmox.com References: <20260319143649.681937-1-c.ebner@proxmox.com> Content-Language: en-US From: Thomas Lamprecht In-Reply-To: <20260319143649.681937-1-c.ebner@proxmox.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Bm-Milter-Handled: 55990f41-d878-4baa-be0a-ee34c49e34d2 X-Bm-Transport-Timestamp: 1774422501659 X-SPAM-LEVEL: Spam detection results: 0 AWL -0.009 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 SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record Message-ID-Hash: OXLOZLAMVIIVMEYA2ZEH2PI6HQMTG2T3 X-Message-ID-Hash: OXLOZLAMVIIVMEYA2ZEH2PI6HQMTG2T3 X-MailFrom: t.lamprecht@proxmox.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; loop; banned-address; emergency; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.10 Precedence: list List-Id: Proxmox Backup Server development discussion List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: Am 19.03.26 um 15:37 schrieb Christian Ebner: > As reported in the community forum [0], the default systemd service > to run fstrim does not cover datastores mounted via systemd mount > unit, since the fstrim command is invoked via: > ``` > fstrim --listed-in /etc/fstab:/proc/self/mountinfo ... > ``` > which however only considers the list up to the first non-empty > file according to the man page [1]. But basically that means systemd would already be totally fine with fstrim'ing all mounted file-systems, not sure if its really worth to reimplement this ourselves, especially given that a single datastore doesn't exactly map to one filesystem. Also, ZFS, a popular choice for datastores, comes with it's own trim handling triggering every first Sunday of a month (see /etc/cron.d/zfsutils-linux). I'd rather prefer leveraging what's existing compared to carry our own implementation here, not just for the (probably not *that* big) maintenance burden, but also because it increases complexity in general by re-implementing parts of systemd ourselves (can be fine, if there's a good reason, I'm not yet convinced that this is one). I'd rather hook into fstrim.service/timer (e.g. through an override that can add another ExecStart). If it turns out that this is so frequently in need for per-datastore configuration with good use cases where such an approach really falls short, we can still provide actual integration into api/ui/... and OTOH, we cannot easily drop such an integration like here again. > To allow for easy configuration of scheduled fstrims also on > filesystems backing datastores in PBS, implement a scheduled job > with per-datastore schedule configuration. Enable and default to > executing the fstrim job for new datastores (except crated via ZFS > dialog). > > Open question remaining: > How to best handle datastores located on ZFS? Should the command default > to zpool trim? Should it set `autotrim=on` on datastore creation instead > and silently ignore as it is now? see above, it's already handled.