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 D51C28A1B for ; Wed, 16 Nov 2022 12:18:31 +0100 (CET) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id B61FE1E4B5 for ; Wed, 16 Nov 2022 12:18:31 +0100 (CET) Received: from proxmox-new.maurer-it.com (proxmox-new.maurer-it.com [94.136.29.106]) (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 firstgate.proxmox.com (Proxmox) with ESMTPS for ; Wed, 16 Nov 2022 12:18:31 +0100 (CET) Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id E135044C8E for ; Wed, 16 Nov 2022 12:18:30 +0100 (CET) Date: Wed, 16 Nov 2022 12:18:23 +0100 From: Fabian =?iso-8859-1?q?Gr=FCnbichler?= To: Proxmox VE development discussion References: <20221107110035.93972-1-f.ebner@proxmox.com> In-Reply-To: <20221107110035.93972-1-f.ebner@proxmox.com> MIME-Version: 1.0 User-Agent: astroid/0.16.0 (https://github.com/astroidmail/astroid) Message-Id: <1668596522.lpeo4rqk2k.astroid@yuna.none> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-SPAM-LEVEL: Spam detection results: =?UTF-8?Q?0=0A=09?=AWL 0.139 Adjusted score from AWL reputation of From: =?UTF-8?Q?address=0A=09?=BAYES_00 -1.9 Bayes spam probability is 0 to 1% KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict =?UTF-8?Q?Alignment=0A=09?=SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF =?UTF-8?Q?Record=0A=09?=SPF_PASS -0.001 SPF: sender matches SPF record Subject: Re: [pve-devel] [PATCH storage 1/2] zfs: only use cache when listing images locally X-BeenThere: pve-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox VE development discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 16 Nov 2022 11:18:31 -0000 On November 7, 2022 12:00 pm, Fiona Ebner wrote: > The plugin for remote ZFS storages currently also uses the same > list_images() as the plugin for local ZFS storages. The issue with > this is that there is only one cache which does not remember the > target host where the information originated. >=20 > Simply restrict the cache to be used for the local ZFS plugin only. An > alternative solution would be to use a cache for each target host, but > that seems a bit more involved and could still be added in the future. wouldn't it be sufficient to just do $cache->{zfs}->{$storeid} when filling/querying the cache, and combining that with *always* listing o= nly the storage-relevant pool? the only case where we actually benefit from listing *all* zfs volumes/data= sets is when - there are multiple storages configured referencing overlapping parts of t= he ZFS hierarchy - vdisk_list is called with a volume_list with multiple such storages being= part of the set, or with $vmid but no $storeid (rescan, or purging unreferenced = guest disks on guest removal) in practice, it likely doesn't make much difference since ZFS should cache = the metadata for the overlapping parts in memory anyway (given that we'd then c= all 'zfs list' in a loop with different starting points). whereas, for most regular cases listing happens without a cache anyway (or = with a cache, but only a single storage involved), so there is no benefit in que= rying volumes belonging to other storages since we are not interested in them any= way. sidenote: it seems like vdisk_list's volume_list is not used anywhere as pa= rameter? >=20 > For example, issues can happen during rescan: > 1. Via list_images() and zfs_list_zvol(), ZFSPlugin.pm's zfs_request() > is executed for a remote ZFS. > 2. $cache->{zfs} is set to the result of scanning the images there. > 3. Another list_images() for a local ZFS storage happens and uses the > cache with the wrong information. >=20 > Signed-off-by: Fiona Ebner