From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate001.proxmox.com (gate001.proxmox.com [IPv6:2a0f:8001:1:32::40]) by lore.proxmox.com (Postfix) with ESMTPS id EC1671FF0E5 for ; Wed, 12 Aug 2026 12:37:53 +0200 (CEST) Received: from gate001.proxmox.com (localhost.localdomain [127.0.0.1]) by gate001.proxmox.com (Proxmox) with ESMTP id AE57421577; Wed, 12 Aug 2026 12:37:53 +0200 (CEST) From: Maximiliano Sandoval To: Fiona Ebner Subject: Re: [RFC storage 3/3] close #7204: lvm thin plugin: die if thin pool does not have zeroing configured In-Reply-To: <20260205163819.219322-4-f.ebner@proxmox.com> (Fiona Ebner's message of "Thu, 5 Feb 2026 17:38:06 +0100") References: <20260205163819.219322-1-f.ebner@proxmox.com> <20260205163819.219322-4-f.ebner@proxmox.com> User-Agent: mu4e 1.12.9; emacs 30.1 Date: Wed, 12 Aug 2026 12:37:50 +0200 Message-ID: MIME-Version: 1.0 Content-Type: text/plain X-Bm-Milter-Handled: 55990f41-d878-4baa-be0a-ee34c49e34d2 X-Bm-Transport-Timestamp: 1786531055990 X-SPAM-LEVEL: Spam detection results: 0 AWL 0.980 Adjusted score from AWL reputation of From: address DMARC_MISSING 0.1 Missing DMARC policy KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment (newer systems) 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 Message-ID-Hash: EB4ABXT3COYLX577XUAXZFR4KTZIPSVI X-Message-ID-Hash: EB4ABXT3COYLX577XUAXZFR4KTZIPSVI X-MailFrom: m.sandoval@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 CC: pve-devel@lists.proxmox.com X-Mailman-Version: 3.3.10 Precedence: list List-Id: Proxmox VE development discussion List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: Fiona Ebner writes: > Thin pools with zeroing during allocation turned off are currently not > supported for VM images. Using such a pool may lead to data > corruption for various operations like drive mirror. > > In the future, a dedicated storage configuration option could be > introduced that can be checked by volume_has_feature() and enforced > upon storage activation. > > Signed-off-by: Fiona Ebner > --- > > RFC - it is rather noisy since pvestatd will log it every time, OTOH > it may cause data corruption so being noisy can be justified. An > alternative might be to just automatically set it after detecting that > the flag is missing and only warn once, mentioning that that this is > done, but might be too much automagic. > > src/PVE/Storage/LvmThinPlugin.pm | 17 ++++++++++++++++- > 1 file changed, 16 insertions(+), 1 deletion(-) > > diff --git a/src/PVE/Storage/LvmThinPlugin.pm b/src/PVE/Storage/LvmThinPlugin.pm > index 256ec43..dae40b6 100644 > --- a/src/PVE/Storage/LvmThinPlugin.pm > +++ b/src/PVE/Storage/LvmThinPlugin.pm > @@ -6,6 +6,7 @@ use warnings; > use IO::File; > > use PVE::JSONSchema qw(get_standard_option); > +use PVE::RESTEnvironment qw(log_warn); > use PVE::Tools qw(run_command trim); > > use PVE::Storage::Plugin; > @@ -263,7 +264,21 @@ sub activate_storage { > > $class->SUPER::activate_storage($storeid, $scfg, $cache); > > - $activate_lv->($scfg->{vgname}, $scfg->{thinpool}, $cache); > + my ($vg_name, $thin_pool) = $scfg->@{qw(vgname thinpool)}; > + > + $activate_lv->($vg_name, $thin_pool, $cache); > + > + if ($scfg->{content}->{images}) { > + my $lvs = $cache->{lvs} ||= PVE::Storage::LVMPlugin::lvm_list_volumes(); > + my $thin_pool_zero = $lvs->{$vg_name}->{$thin_pool}->{zero}; > + if (!defined($thin_pool_zero) || $thin_pool_zero ne 'zero') { > + # TODO Add dedicated storage configuration option to support thin pools without zero to > + # allow cheap checking in volume_has_feature() and check that it matches here. > + # TODO PVE 10 - enforce? > + log_warn("$storeid: thin pool without zeroing is not supported for VM images!" > + . " Use 'lvchange -Z y $vg_name/$thin_pool' to enable zeroing"); nit: If there is a new version, can we use the full --zero=y flag here? > + } > + } > } > > sub activate_volume { -- Maximiliano